From cf0a475a2e501f21638369eca6ceb090ef47bd51 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Thu, 10 Jun 2021 22:00:59 +0700
Subject: [PATCH 01/19] clean up

---
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 101 ++++++++++---------
 1 file changed, 56 insertions(+), 45 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index b575c6afc..7042160ec 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -52,22 +52,23 @@
 static_assert(PICO_USB_HOST_INTERRUPT_ENDPOINTS <= USB_MAX_ENDPOINTS, "");
 
 // Host mode uses one shared endpoint register for non-interrupt endpoint
-struct hw_endpoint eps[1 + PICO_USB_HOST_INTERRUPT_ENDPOINTS];
-#define epx (eps[0])
+static struct hw_endpoint ep_pool[1 + PICO_USB_HOST_INTERRUPT_ENDPOINTS];
+#define epx (ep_pool[0])
 
-#define usb_hw_set hw_set_alias(usb_hw)
+#define usb_hw_set   hw_set_alias(usb_hw)
 #define usb_hw_clear hw_clear_alias(usb_hw)
 
-// Used for hcd pipe busy.
 // todo still a bit wasteful
 // top bit set if valid
 uint8_t dev_ep_map[CFG_TUSB_HOST_DEVICE_MAX][1 + PICO_USB_HOST_INTERRUPT_ENDPOINTS][2];
 
 // Flags we set by default in sie_ctrl (we add other bits on top)
-static uint32_t sie_ctrl_base = USB_SIE_CTRL_SOF_EN_BITS | 
-                                USB_SIE_CTRL_KEEP_ALIVE_EN_BITS | 
-                                USB_SIE_CTRL_PULLDOWN_EN_BITS | 
-                                USB_SIE_CTRL_EP0_INT_1BUF_BITS;
+enum {
+  sie_ctrl_base = USB_SIE_CTRL_SOF_EN_BITS        |
+                  USB_SIE_CTRL_KEEP_ALIVE_EN_BITS |
+                  USB_SIE_CTRL_PULLDOWN_EN_BITS   |
+                  USB_SIE_CTRL_EP0_INT_1BUF_BITS
+};
 
 static struct hw_endpoint *get_dev_ep(uint8_t dev_addr, uint8_t ep_addr)
 {
@@ -78,19 +79,22 @@ static struct hw_endpoint *get_dev_ep(uint8_t dev_addr, uint8_t ep_addr)
     uint8_t in = (ep_addr & TUSB_DIR_IN_MASK) ? 1 : 0;
     uint mapping = dev_ep_map[dev_addr-1][num][in];
     pico_trace("Get dev addr %d ep %d = %d\n", dev_addr, ep_addr, mapping);
-    return mapping >= 128 ? eps + (mapping & 0x7fu) : NULL;
+    return mapping >= 128 ? ep_pool + (mapping & 0x7fu) : NULL;
 }
 
 static void set_dev_ep(uint8_t dev_addr, uint8_t ep_addr, struct hw_endpoint *ep)
 {
     uint8_t num = tu_edpt_number(ep_addr);
-    uint8_t in = (ep_addr & TUSB_DIR_IN_MASK) ? 1 : 0;
-    uint32_t index = ep - eps;
-    hard_assert(index < TU_ARRAY_SIZE(eps));
+    uint8_t in = (uint8_t) tu_edpt_dir(ep_addr);
+
+    uint32_t index = ep - ep_pool;
+    hard_assert(index < TU_ARRAY_SIZE(ep_pool));
+
     // todo revisit why dev_addr can be 0 here
     if (dev_addr) {
         dev_ep_map[dev_addr-1][num][in] = 128u | index;
     }
+
     pico_trace("Set dev addr %d ep %d = %d\n", dev_addr, ep_addr, index);
 }
 
@@ -153,7 +157,7 @@ static void hw_handle_buff_status(void)
         if (remaining_buffers & bit)
         {
             remaining_buffers &= ~bit;
-            _handle_buff_status_bit(bit, &eps[i]);
+            _handle_buff_status_bit(bit, &ep_pool[i]);
         }
     }
 
@@ -206,13 +210,15 @@ static void hcd_rp2040_irq(void)
     {
         handled |= USB_INTS_TRANS_COMPLETE_BITS;
         usb_hw_clear->sie_status = USB_SIE_STATUS_TRANS_COMPLETE_BITS;
+        TU_LOG(2, "Transfer complete\n");
         hw_trans_complete();
     }
 
     if (status & USB_INTS_BUFF_STATUS_BITS)
     {
         handled |= USB_INTS_BUFF_STATUS_BITS;
-        // print_bufctrl32(*epx.buffer_control);
+        TU_LOG(2, "Buffer complete\n");
+        print_bufctrl32(*epx.buffer_control);
         hw_handle_buff_status();
     }
 
@@ -234,7 +240,7 @@ static void hcd_rp2040_irq(void)
     if (status & USB_INTS_ERROR_DATA_SEQ_BITS)
     {
         usb_hw_clear->sie_status = USB_SIE_STATUS_DATA_SEQ_ERROR_BITS;
-        // print_bufctrl32(*epx.buffer_control);
+        print_bufctrl32(*epx.buffer_control);
         panic("Data Seq Error \n");
     }
 
@@ -247,9 +253,9 @@ static void hcd_rp2040_irq(void)
 static struct hw_endpoint *_next_free_interrupt_ep(void)
 {
     struct hw_endpoint *ep = NULL;
-    for (uint i = 1; i < TU_ARRAY_SIZE(eps); i++)
+    for (uint i = 1; i < TU_ARRAY_SIZE(ep_pool); i++)
     {
-        ep = &eps[i];
+        ep = &ep_pool[i];
         if (!ep->configured)
         {
             // Will be configured by _hw_endpoint_init / _hw_endpoint_allocate
@@ -263,6 +269,7 @@ static struct hw_endpoint *_next_free_interrupt_ep(void)
 static struct hw_endpoint *_hw_endpoint_allocate(uint8_t transfer_type)
 {
     struct hw_endpoint *ep = NULL;
+
     if (transfer_type == TUSB_XFER_INTERRUPT)
     {
         ep = _next_free_interrupt_ep();
@@ -283,6 +290,7 @@ static struct hw_endpoint *_hw_endpoint_allocate(uint8_t transfer_type)
         ep->endpoint_control = &usbh_dpram->epx_ctrl;
         ep->hw_data_buf = &usbh_dpram->epx_data[0];
     }
+
     return ep;
 }
 
@@ -345,24 +353,9 @@ static void _hw_endpoint_init(struct hw_endpoint *ep, uint8_t dev_addr, uint8_t
 
         // If it's an interrupt endpoint we need to set up the buffer control
         // register
-
     }
 }
 
-static void hw_endpoint_init(uint8_t dev_addr, const tusb_desc_endpoint_t *ep_desc)
-{
-    // Allocated differently based on if it's an interrupt endpoint or not
-    struct hw_endpoint *ep = _hw_endpoint_allocate(ep_desc->bmAttributes.xfer);
-    _hw_endpoint_init(ep,
-        dev_addr,
-        ep_desc->bEndpointAddress,
-        ep_desc->wMaxPacketSize.size,
-        ep_desc->bmAttributes.xfer,
-        ep_desc->bInterval);
-    // Map this struct to ep@device address
-    set_dev_ep(dev_addr, ep_desc->bEndpointAddress, ep);
-}
-
 //--------------------------------------------------------------------+
 // HCD API
 //--------------------------------------------------------------------+
@@ -377,7 +370,7 @@ bool hcd_init(uint8_t rhport)
     irq_set_exclusive_handler(USBCTRL_IRQ, hcd_rp2040_irq);
 
     // clear epx and interrupt eps
-    memset(&eps, 0, sizeof(eps));
+    memset(&ep_pool, 0, sizeof(ep_pool));
 
     // Enable in host mode with SOF / Keep alive on
     usb_hw->main_ctrl = USB_MAIN_CTRL_CONTROLLER_EN_BITS | USB_MAIN_CTRL_HOST_NDEVICE_BITS;
@@ -420,6 +413,7 @@ tusb_speed_t hcd_port_speed_get(uint8_t rhport)
             return TUSB_SPEED_FULL;
         default:
             panic("Invalid speed\n");
+            return TUSB_SPEED_INVALID;
     }
 }
 
@@ -444,7 +438,7 @@ void hcd_int_disable(uint8_t rhport)
 
 bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t * buffer, uint16_t buflen)
 {
-    pico_info("hcd_edpt_xfer dev_addr %d, ep_addr 0x%x, len %d\n", dev_addr, ep_addr, buflen);
+    pico_trace("hcd_edpt_xfer dev_addr %d, ep_addr 0x%x, len %d\n", dev_addr, ep_addr, buflen);
     
     // Get appropriate ep. Either EPX or interrupt endpoint
     struct hw_endpoint *ep = get_dev_ep(dev_addr, ep_addr);
@@ -452,13 +446,12 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
 
     if (ep_addr != ep->ep_addr)
     {
-        // Direction has flipped so re init it but with same properties
-        // TODO treat IN and OUT as invidual endpoints
+        // Direction has flipped on endpoint control so re init it but with same properties
         _hw_endpoint_init(ep, dev_addr, ep_addr, ep->wMaxPacketSize, ep->transfer_type, 0);
     }
 
     // True indicates this is the start of the transfer
-    _hw_endpoint_xfer(ep, buffer, buflen, true);
+    _hw_endpoint_xfer_start(ep, buffer, buflen);
 
     // If a normal transfer (non-interrupt) then initiate using
     // sie ctrl registers. Otherwise interrupt ep registers should
@@ -479,27 +472,30 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
 
 bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet[8])
 {
-    pico_info("hcd_setup_send dev_addr %d\n", dev_addr);
-    
     // Copy data into setup packet buffer
     memcpy((void*)&usbh_dpram->setup_packet[0], setup_packet, 8);
 
     // Configure EP0 struct with setup info for the trans complete
     struct hw_endpoint *ep = _hw_endpoint_allocate(0);
+
     // EP0 out
     _hw_endpoint_init(ep, dev_addr, 0x00, ep->wMaxPacketSize, 0, 0);
     assert(ep->configured);
-    ep->total_len = 8;
+
+    ep->total_len     = 8;
     ep->transfer_size = 8;
-    ep->active = true;
-    ep->sent_setup = true;
+    ep->active        = true;
+    ep->sent_setup    = true;
 
     // Set device address
     usb_hw->dev_addr_ctrl = dev_addr;
+
     // Set pre if we are a low speed device on full speed hub
-    uint32_t flags = sie_ctrl_base | USB_SIE_CTRL_SEND_SETUP_BITS | USB_SIE_CTRL_START_TRANS_BITS;
-    flags |= need_pre(dev_addr) ? USB_SIE_CTRL_PREAMBLE_EN_BITS : 0;
+    uint32_t const flags = sie_ctrl_base | USB_SIE_CTRL_SEND_SETUP_BITS | USB_SIE_CTRL_START_TRANS_BITS |
+                           (need_pre(dev_addr) ? USB_SIE_CTRL_PREAMBLE_EN_BITS : 0);
+
     usb_hw->sie_ctrl = flags;
+
     return true;
 }
 
@@ -510,8 +506,23 @@ uint32_t hcd_frame_number(uint8_t rhport)
 
 bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const * ep_desc)
 {
+    (void) rhport;
+
     pico_trace("hcd_edpt_open dev_addr %d, ep_addr %d\n", dev_addr, ep_desc->bEndpointAddress);
-    hw_endpoint_init(dev_addr, ep_desc);
+
+    // Allocated differently based on if it's an interrupt endpoint or not
+    struct hw_endpoint *ep = _hw_endpoint_allocate(ep_desc->bmAttributes.xfer);
+
+    _hw_endpoint_init(ep,
+        dev_addr,
+        ep_desc->bEndpointAddress,
+        ep_desc->wMaxPacketSize.size,
+        ep_desc->bmAttributes.xfer,
+        ep_desc->bInterval);
+
+    // Map this struct to ep@device address
+    set_dev_ep(dev_addr, ep_desc->bEndpointAddress, ep);
+
     return true;
 }
 

From 43656dc0a7a613f8d5f6533d2c68ca9f5824a5f4 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Thu, 10 Jun 2021 23:29:02 +0700
Subject: [PATCH 02/19] more clean up

---
 src/host/usbh_control.c                      |  2 +-
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 77 ++++++++++++--------
 2 files changed, 48 insertions(+), 31 deletions(-)

diff --git a/src/host/usbh_control.c b/src/host/usbh_control.c
index 4dbf8592a..aa82f14ba 100644
--- a/src/host/usbh_control.c
+++ b/src/host/usbh_control.c
@@ -68,7 +68,7 @@ bool tuh_control_xfer (uint8_t dev_addr, tusb_control_request_t const* request,
   _ctrl_xfer.stage       = STAGE_SETUP;
   _ctrl_xfer.complete_cb = complete_cb;
 
-  TU_LOG2("Control Setup: ");
+  TU_LOG2("Send Setup to address %u: ", dev_addr);
   TU_LOG2_VAR(request);
   TU_LOG2("\r\n");
 
diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index 7042160ec..d6bcf5b82 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -420,9 +420,18 @@ tusb_speed_t hcd_port_speed_get(uint8_t rhport)
 // Close all opened endpoint belong to this device
 void hcd_device_close(uint8_t rhport, uint8_t dev_addr)
 {
+    (void) rhport;
+    (void) dev_addr;
+
     pico_trace("hcd_device_close %d\n", dev_addr);
 }
 
+uint32_t hcd_frame_number(uint8_t rhport)
+{
+    (void) rhport;
+    return usb_hw->sof_rd;
+}
+
 void hcd_int_enable(uint8_t rhport)
 {
     assert(rhport == 0);
@@ -436,10 +445,37 @@ void hcd_int_disable(uint8_t rhport)
     irq_set_enabled(USBCTRL_IRQ, false);
 }
 
+bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const * ep_desc)
+{
+    (void) rhport;
+
+    pico_trace("hcd_edpt_open dev_addr %d, ep_addr %d\n", dev_addr, ep_desc->bEndpointAddress);
+
+    // Allocated differently based on if it's an interrupt endpoint or not
+    struct hw_endpoint *ep = _hw_endpoint_allocate(ep_desc->bmAttributes.xfer);
+
+    _hw_endpoint_init(ep,
+        dev_addr,
+        ep_desc->bEndpointAddress,
+        ep_desc->wMaxPacketSize.size,
+        ep_desc->bmAttributes.xfer,
+        ep_desc->bInterval);
+
+    // Map this struct to ep@device address
+    set_dev_ep(dev_addr, ep_desc->bEndpointAddress, ep);
+
+    return true;
+}
+
 bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t * buffer, uint16_t buflen)
 {
+    (void) rhport;
+
     pico_trace("hcd_edpt_xfer dev_addr %d, ep_addr 0x%x, len %d\n", dev_addr, ep_addr, buflen);
     
+    uint8_t const ep_num = tu_edpt_number(ep_addr);
+    tusb_dir_t const ep_dir = tu_edpt_dir(ep_addr);
+
     // Get appropriate ep. Either EPX or interrupt endpoint
     struct hw_endpoint *ep = get_dev_ep(dev_addr, ep_addr);
     assert(ep);
@@ -450,7 +486,7 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
         _hw_endpoint_init(ep, dev_addr, ep_addr, ep->wMaxPacketSize, ep->transfer_type, 0);
     }
 
-    // True indicates this is the start of the transfer
+    // Start the transfer
     _hw_endpoint_xfer_start(ep, buffer, buflen);
 
     // If a normal transfer (non-interrupt) then initiate using
@@ -459,11 +495,13 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
     if (ep == &epx) {
         // That has set up buffer control, endpoint control etc
         // for host we have to initiate the transfer
-        usb_hw->dev_addr_ctrl = dev_addr | (tu_edpt_number(ep_addr) << USB_ADDR_ENDP_ENDPOINT_LSB);
-        uint32_t flags = USB_SIE_CTRL_START_TRANS_BITS | sie_ctrl_base;
-        flags |= ep->rx ? USB_SIE_CTRL_RECEIVE_DATA_BITS : USB_SIE_CTRL_SEND_DATA_BITS;
+        usb_hw->dev_addr_ctrl = dev_addr | (ep_num << USB_ADDR_ENDP_ENDPOINT_LSB);
+
+        uint32_t flags = USB_SIE_CTRL_START_TRANS_BITS | sie_ctrl_base |
+                         (ep_dir ? USB_SIE_CTRL_RECEIVE_DATA_BITS : USB_SIE_CTRL_SEND_DATA_BITS);
         // Set pre if we are a low speed device on full speed hub
         flags |= need_pre(dev_addr) ? USB_SIE_CTRL_PREAMBLE_EN_BITS : 0;
+
         usb_hw->sie_ctrl = flags;
     }
 
@@ -472,6 +510,8 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
 
 bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet[8])
 {
+    (void) rhport;
+
     // Copy data into setup packet buffer
     memcpy((void*)&usbh_dpram->setup_packet[0], setup_packet, 8);
 
@@ -499,32 +539,6 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
     return true;
 }
 
-uint32_t hcd_frame_number(uint8_t rhport)
-{
-    return usb_hw->sof_rd;
-}
-
-bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const * ep_desc)
-{
-    (void) rhport;
-
-    pico_trace("hcd_edpt_open dev_addr %d, ep_addr %d\n", dev_addr, ep_desc->bEndpointAddress);
-
-    // Allocated differently based on if it's an interrupt endpoint or not
-    struct hw_endpoint *ep = _hw_endpoint_allocate(ep_desc->bmAttributes.xfer);
-
-    _hw_endpoint_init(ep,
-        dev_addr,
-        ep_desc->bEndpointAddress,
-        ep_desc->wMaxPacketSize.size,
-        ep_desc->bmAttributes.xfer,
-        ep_desc->bInterval);
-
-    // Map this struct to ep@device address
-    set_dev_ep(dev_addr, ep_desc->bEndpointAddress, ep);
-
-    return true;
-}
 
 //bool hcd_edpt_busy(uint8_t dev_addr, uint8_t ep_addr)
 //{
@@ -542,6 +556,9 @@ bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const
 
 bool hcd_edpt_clear_stall(uint8_t dev_addr, uint8_t ep_addr)
 {
+    (void) rhport;
+    (void) dev_addr;
+
     panic("hcd_clear_stall");
     return true;
 }

From a1a03c92f66e0c2cae5198341c322182302a1229 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 17:05:49 +0700
Subject: [PATCH 03/19] double buffered work with host

---
 src/portable/raspberrypi/rp2040/dcd_rp2040.c |  10 +-
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 103 ++++++-
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 267 +++++++++----------
 src/portable/raspberrypi/rp2040/rp2040_usb.h |  15 +-
 4 files changed, 233 insertions(+), 162 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index 0048270a6..ccdbb9c01 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -198,10 +198,10 @@ static void hw_endpoint_init(uint8_t ep_addr, uint16_t wMaxPacketSize, uint8_t b
     _hw_endpoint_init(ep, ep_addr, wMaxPacketSize, bmAttributes);
 }
 
-static void hw_endpoint_xfer(uint8_t ep_addr, uint8_t *buffer, uint16_t total_bytes, bool start)
+static void hw_endpoint_xfer(uint8_t ep_addr, uint8_t *buffer, uint16_t total_bytes)
 {
     struct hw_endpoint *ep = hw_endpoint_get_by_addr(ep_addr);
-    _hw_endpoint_xfer(ep, buffer, total_bytes, start);
+    _hw_endpoint_xfer_start(ep, buffer, total_bytes);
 }
 
 static void hw_handle_buff_status(void)
@@ -251,7 +251,7 @@ static void ep0_0len_status(void)
 {
     // Send 0len complete response on EP0 IN
     reset_ep0();
-    hw_endpoint_xfer(0x80, NULL, 0, true);
+    hw_endpoint_xfer(0x80, NULL, 0);
 }
 
 static void _hw_endpoint_stall(struct hw_endpoint *ep)
@@ -477,7 +477,7 @@ void dcd_edpt0_status_complete(uint8_t rhport, tusb_control_request_t const * re
         request->bmRequestType_bit.type == TUSB_REQ_TYPE_STANDARD &&
         request->bRequest == TUSB_REQ_SET_ADDRESS)
     {
-        pico_trace("Set HW address %d\n", assigned_address);
+        pico_trace("Set HW address %d\n", request->wValue);
         usb_hw->dev_addr_ctrl = (uint8_t) request->wValue;
     }
 
@@ -496,7 +496,7 @@ bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t t
 {
     assert(rhport == 0);
     // True means start new xfer
-    hw_endpoint_xfer(ep_addr, buffer, total_bytes, true);
+    hw_endpoint_xfer(ep_addr, buffer, total_bytes);
     return true;
 }
 
diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index d6bcf5b82..561656a10 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -115,9 +115,9 @@ static void hw_xfer_complete(struct hw_endpoint *ep, xfer_result_t xfer_result)
     // Mark transfer as done before we tell the tinyusb stack
     uint8_t dev_addr = ep->dev_addr;
     uint8_t ep_addr = ep->ep_addr;
-    uint total_len = ep->total_len;
+    uint xferred_len = ep->len;
     hw_endpoint_reset_transfer(ep);
-    hcd_event_xfer_complete(dev_addr, ep_addr, total_len, xfer_result, true);
+    hcd_event_xfer_complete(dev_addr, ep_addr, xferred_len, xfer_result, true);
 }
 
 static void _handle_buff_status_bit(uint bit, struct hw_endpoint *ep)
@@ -141,6 +141,20 @@ static void hw_handle_buff_status(void)
     {
         remaining_buffers &= ~bit;
         struct hw_endpoint *ep = &epx;
+
+        uint32_t ep_ctrl = *ep->endpoint_control;
+        if (ep_ctrl & EP_CTRL_DOUBLE_BUFFERED_BITS)
+        {
+          TU_LOG(2, "Double Buffered ");
+        }else
+        {
+          TU_LOG(2, "Single Buffered ");
+        }
+
+        if (ep_ctrl & EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER) TU_LOG(2, "Interrupt per double ");
+        if (ep_ctrl & EP_CTRL_INTERRUPT_PER_BUFFER) TU_LOG(2, "Interrupt per single ");
+        TU_LOG_HEX(2, ep_ctrl);
+
         _handle_buff_status_bit(bit, ep);
     }
 
@@ -277,11 +291,11 @@ static struct hw_endpoint *_hw_endpoint_allocate(uint8_t transfer_type)
         assert(ep);
         ep->buffer_control = &usbh_dpram->int_ep_buffer_ctrl[ep->interrupt_num].ctrl;
         ep->endpoint_control = &usbh_dpram->int_ep_ctrl[ep->interrupt_num].ctrl;
-        // 0x180 for epx
-        // 0x1c0 for intep0
-        // 0x200 for intep1
+        // 0 for epx (double buffered): TODO increase to 1024 for ISO
+        // 2x64 for intep0
+        // 3x64 for intep1
         // etc
-        ep->hw_data_buf = &usbh_dpram->epx_data[64 * (ep->interrupt_num + 1)];
+        ep->hw_data_buf = &usbh_dpram->epx_data[64 * (ep->interrupt_num + 2)];
     }
     else
     {
@@ -311,7 +325,7 @@ static void _hw_endpoint_init(struct hw_endpoint *ep, uint8_t dev_addr, uint8_t
     ep->rx = (dir == TUSB_DIR_IN);
 
     // Response to a setup packet on EP0 starts with pid of 1
-    ep->next_pid = num == 0 ? 1u : 0u;
+    ep->next_pid = (num == 0 ? 1u : 0u);
     ep->wMaxPacketSize = wMaxPacketSize;
     ep->transfer_type = transfer_type;
 
@@ -340,6 +354,7 @@ static void _hw_endpoint_init(struct hw_endpoint *ep, uint8_t dev_addr, uint8_t
         // preamble
         uint32_t reg = dev_addr | (num << USB_ADDR_ENDP1_ENDPOINT_LSB);
         // Assert the interrupt endpoint is IN_TO_HOST
+        // TODO Interrupt can also be OUT
         assert(dir == TUSB_DIR_IN);
 
         if (need_pre(dev_addr))
@@ -402,7 +417,6 @@ bool hcd_port_connect_status(uint8_t rhport)
 
 tusb_speed_t hcd_port_speed_get(uint8_t rhport)
 {
-    pico_trace("hcd_port_speed_get\n");
     assert(rhport == 0);
     // TODO: Should enumval this register
     switch (dev_speed())
@@ -445,6 +459,10 @@ void hcd_int_disable(uint8_t rhport)
     irq_set_enabled(USBCTRL_IRQ, false);
 }
 
+//--------------------------------------------------------------------+
+// Endpoint API
+//--------------------------------------------------------------------+
+
 bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const * ep_desc)
 {
     (void) rhport;
@@ -467,6 +485,65 @@ bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const
     return true;
 }
 
+// return true if double buffered
+static bool xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len)
+{
+  // Fill in info now that we're kicking off the hw
+  ep->total_len = total_len;
+  ep->len = 0;
+
+  // Limit by packet size
+  ep->user_buf = buffer;
+
+  // Buffer 0
+  ep->transfer_size = tu_min16(total_len, ep->wMaxPacketSize);
+  total_len -= ep->transfer_size;
+
+  // Buffer 1
+  ep->buf_1_len = tu_min16(total_len, ep->wMaxPacketSize);
+  total_len -= ep->buf_1_len;
+
+  ep->active = true;
+
+  // Write buffer control
+
+  // Buffer 0
+  uint32_t bufctrl = ep->transfer_size  | USB_BUF_CTRL_AVAIL;
+
+  // Copy data to DPB if tx
+  if (!ep->rx)
+  {
+    // Copy data from user buffer to hw buffer
+    memcpy(ep->hw_data_buf, ep->user_buf, ep->transfer_size + ep->buf_1_len);
+
+    // Mark as full
+    bufctrl |= USB_BUF_CTRL_FULL | (ep->buf_1_len ? (USB_BUF_CTRL_FULL << 16) : 0);
+  }
+
+  // PID
+  bufctrl |= ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID;
+  ep->next_pid ^= 1u;
+
+  if (ep->buf_1_len)
+  {
+    bufctrl |= (ep->buf_1_len | USB_BUF_CTRL_AVAIL) << 16;
+    bufctrl |= (ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID) << 16;
+    ep->next_pid ^= 1u;
+  }
+
+  // determine which buffer is last
+  if (total_len == 0)
+  {
+    bufctrl |= USB_BUF_CTRL_LAST << (ep->buf_1_len ? 16 : 0);
+  }
+
+  print_bufctrl32(bufctrl);
+
+  _hw_endpoint_buffer_control_set_value32(ep, bufctrl);
+
+  return ep->buf_1_len > 0;
+}
+
 bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t * buffer, uint16_t buflen)
 {
     (void) rhport;
@@ -486,13 +563,12 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
         _hw_endpoint_init(ep, dev_addr, ep_addr, ep->wMaxPacketSize, ep->transfer_type, 0);
     }
 
-    // Start the transfer
-    _hw_endpoint_xfer_start(ep, buffer, buflen);
-
     // If a normal transfer (non-interrupt) then initiate using
     // sie ctrl registers. Otherwise interrupt ep registers should
     // already be configured
     if (ep == &epx) {
+        _hw_endpoint_xfer_start(ep, buffer, buflen);
+
         // That has set up buffer control, endpoint control etc
         // for host we have to initiate the transfer
         usb_hw->dev_addr_ctrl = dev_addr | (ep_num << USB_ADDR_ENDP_ENDPOINT_LSB);
@@ -503,6 +579,9 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
         flags |= need_pre(dev_addr) ? USB_SIE_CTRL_PREAMBLE_EN_BITS : 0;
 
         usb_hw->sie_ctrl = flags;
+    }else
+    {
+      _hw_endpoint_xfer_start(ep, buffer, buflen);
     }
 
     return true;
@@ -556,8 +635,8 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
 
 bool hcd_edpt_clear_stall(uint8_t dev_addr, uint8_t ep_addr)
 {
-    (void) rhport;
     (void) dev_addr;
+    (void) ep_addr;
 
     panic("hcd_clear_stall");
     return true;
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 31381e6c2..5f61f90c5 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -61,11 +61,11 @@ void rp2040_usb_init(void)
     memset(usb_dpram, 0, sizeof(*usb_dpram));
 
     // Mux the controller to the onboard usb phy
-    usb_hw->muxing    = USB_USB_MUXING_TO_PHY_BITS    | USB_USB_MUXING_SOFTCON_BITS;
+    usb_hw->muxing = USB_USB_MUXING_TO_PHY_BITS    | USB_USB_MUXING_SOFTCON_BITS;
 
     // Force VBUS detect so the device thinks it is plugged into a host
     // TODO support VBUs detect
-    usb_hw->pwr       = USB_USB_PWR_VBUS_DETECT_BITS  | USB_USB_PWR_VBUS_DETECT_OVERRIDE_EN_BITS;
+    usb_hw->pwr    = USB_USB_PWR_VBUS_DETECT_BITS  | USB_USB_PWR_VBUS_DETECT_OVERRIDE_EN_BITS;
 }
 
 void hw_endpoint_reset_transfer(struct hw_endpoint *ep)
@@ -111,150 +111,157 @@ void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_m
     *ep->buffer_control = value;
 }
 
+// Prepare buffer control register value
 void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
 {
-    // Prepare buffer control register value
-    uint32_t val = ep->transfer_size | USB_BUF_CTRL_AVAIL;
+  uint16_t remaining = ep->total_len - ep->len;
+  uint32_t ep_ctrl = *ep->endpoint_control;
+  uint32_t buf_ctrl;
 
-    if (!ep->rx)
-    {
-        // Copy data from user buffer to hw buffer
-        memcpy(ep->hw_data_buf, &ep->user_buf[ep->len], ep->transfer_size);
-        // Mark as full
-        val |= USB_BUF_CTRL_FULL;
-    }
+  // Buffer 0
+  ep->transfer_size = tu_min16(remaining, ep->wMaxPacketSize);
+  remaining -= ep->transfer_size;
 
-    // PID
-    val |= ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID;
+  buf_ctrl = ep->transfer_size | USB_BUF_CTRL_AVAIL;
+  if ( !ep->rx )
+  {
+    // Copy data from user buffer to hw buffer
+    memcpy(ep->hw_data_buf, ep->user_buf+ep->len, ep->transfer_size);
 
-#if TUSB_OPT_DEVICE_ENABLED
+    // Mark as full
+    buf_ctrl |= USB_BUF_CTRL_FULL;
+  }
+
+  // PID
+  buf_ctrl |= ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID;
+  ep->next_pid ^= 1u;
+
+  // Buffer 1
+  ep->buf_1_len = tu_min16(remaining, ep->wMaxPacketSize);
+  remaining -= ep->buf_1_len;
+
+  if (ep->buf_1_len)
+  {
+    buf_ctrl |= (ep->buf_1_len | USB_BUF_CTRL_AVAIL) << 16;
+    buf_ctrl |= (ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID) << 16;
     ep->next_pid ^= 1u;
 
-#else
-    // For Host (also device but since we dictate the endpoint size, following scenario does not occur)
-    // Next PID depends on the number of packet in case wMaxPacketSize < 64 (e.g Interrupt Endpoint 8, or 12)
-    // Special case with control status stage where PID is always DATA1
-    if ( ep->transfer_size == 0 )
+    if ( !ep->rx )
     {
-      // ZLP also toggle data
-      ep->next_pid ^= 1u;
-    }else
-    {
-      uint32_t packet_count = 1 + ((ep->transfer_size - 1) / ep->wMaxPacketSize);
-
-      if ( packet_count & 0x01 )
-      {
-        ep->next_pid ^= 1u;
-      }
+      // Copy data from user buffer to hw buffer
+      memcpy(ep->hw_data_buf+64, ep->user_buf+ep->len+ep->transfer_size, ep->buf_1_len);
     }
-#endif
 
+    // Set endpoint control double buffered bit if needed
+    ep_ctrl &= ~EP_CTRL_INTERRUPT_PER_BUFFER;
+    ep_ctrl |= EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER;
+  }else
+  {
+    ep_ctrl &= ~(EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER);
+    ep_ctrl |= EP_CTRL_INTERRUPT_PER_BUFFER;
+  }
+
+  *ep->endpoint_control = ep_ctrl;
 
 #if TUSB_OPT_HOST_ENABLED
-    // Is this the last buffer? Only really matters for host mode. Will trigger
-    // the trans complete irq but also stop it polling. We only really care about
-    // trans complete for setup packets being sent
-    if (ep->last_buf)
-    {
-        pico_trace("Last buf (%d bytes left)\n", ep->transfer_size);
-        val |= USB_BUF_CTRL_LAST;
-    }
+  // Is this the last buffer? Only really matters for host mode. Will trigger
+  // the trans complete irq but also stop it polling. We only really care about
+  // trans complete for setup packets being sent
+  if (remaining == 0)
+  {
+    buf_ctrl |= USB_BUF_CTRL_LAST << (ep->buf_1_len ? 16 : 0);
+  }
 #endif
 
-    // Finally, write to buffer_control which will trigger the transfer
-    // the next time the controller polls this dpram address
-    _hw_endpoint_buffer_control_set_value32(ep, val);
-    pico_trace("buffer control (0x%p) <- 0x%x\n", ep->buffer_control, val);
-    //print_bufctrl16(val);
+  print_bufctrl32(buf_ctrl);
+
+  // Finally, write to buffer_control which will trigger the transfer
+  // the next time the controller polls this dpram address
+  _hw_endpoint_buffer_control_set_value32(ep, buf_ctrl);
 }
 
 
 void _hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len)
 {
-    _hw_endpoint_lock_update(ep, 1);
-    pico_trace("Start transfer of total len %d on ep %d %s\n", total_len, tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
-    if (ep->active)
-    {
-        // TODO: Is this acceptable for interrupt packets?
-        pico_warn("WARN: starting new transfer on already active ep %d %s\n", tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
+  _hw_endpoint_lock_update(ep, 1);
+  pico_trace("Start transfer of total len %d on ep %d %s\n", total_len, tu_edpt_number(ep->ep_addr),
+             ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
+  if ( ep->active )
+  {
+    // TODO: Is this acceptable for interrupt packets?
+    pico_warn("WARN: starting new transfer on already active ep %d %s\n", tu_edpt_number(ep->ep_addr),
+              ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
 
-        hw_endpoint_reset_transfer(ep);
-    }
+    hw_endpoint_reset_transfer(ep);
+  }
 
-    // Fill in info now that we're kicking off the hw
-    ep->total_len = total_len;
-    ep->len = 0;
+  // Fill in info now that we're kicking off the hw
+  ep->total_len = total_len;
+  ep->len       = 0;
+  ep->active    = true;
+  ep->user_buf  = buffer;
 
-    // Limit by packet size but not less 64 (i.e low speed 8 bytes EP0)
-    ep->transfer_size = tu_min16(total_len, tu_max16(64, ep->wMaxPacketSize));
-
-    ep->active = true;
-    ep->user_buf = buffer;
-#if TUSB_OPT_HOST_ENABLED
-    // Recalculate if this is the last buffer
-    _hw_endpoint_update_last_buf(ep);
-    ep->buf_sel = 0;
-#endif
-
-    _hw_endpoint_start_next_buffer(ep);
-    _hw_endpoint_lock_update(ep, -1);
+  _hw_endpoint_start_next_buffer(ep);
+  _hw_endpoint_lock_update(ep, -1);
 }
 
-void _hw_endpoint_xfer_sync(struct hw_endpoint *ep)
+void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
 {
-    // Update hw endpoint struct with info from hardware
-    // after a buff status interrupt
+  // Update hw endpoint struct with info from hardware
+  // after a buff status interrupt
 
-    uint32_t buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
+  uint32_t const buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
+  print_bufctrl32(buf_ctrl);
 
-#if TUSB_OPT_HOST_ENABLED
-    // RP2040-E4
-    // tag::host_buf_sel_fix[]
-    // TODO need changes to support double buffering
-    if (ep->buf_sel == 1)
+  // Transferred bytes for each buffer
+  uint16_t xferred_bytes[2];
+
+  xferred_bytes[0] = buf_ctrl & USB_BUF_CTRL_LEN_MASK;
+
+  // double buffered: take buffer1 into account as well
+  if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
+  {
+    xferred_bytes[1] = (buf_ctrl >> 16) & USB_BUF_CTRL_LEN_MASK;
+  }else
+  {
+    xferred_bytes[1] = 0;
+  }
+
+  TU_LOG_INT(2, xferred_bytes[0]);
+  TU_LOG_INT(2, xferred_bytes[1]);
+
+  // We are continuing a transfer here. If we are TX, we have successfully
+  // sent some data can increase the length we have sent
+  if ( !ep->rx )
+  {
+    assert(!(buf_ctrl & USB_BUF_CTRL_FULL));
+    ep->len += xferred_bytes[0] + xferred_bytes[1];
+  }
+  else
+  {
+    // If we are OUT we have recieved some data, so can increase the length
+    // we have recieved AFTER we have copied it to the user buffer at the appropriate offset
+    assert(buf_ctrl & USB_BUF_CTRL_FULL);
+
+    memcpy(&ep->user_buf[ep->len], ep->hw_data_buf, xferred_bytes[0]);
+    ep->len += xferred_bytes[0];
+
+    if (xferred_bytes[1])
     {
-        // Host can erroneously write status to top half of buf_ctrl register
-        buf_ctrl = buf_ctrl >> 16;
-
-        // update buf1 -> buf0 to prevent panic with "already available"
-        *ep->buffer_control = buf_ctrl;
+      memcpy(&ep->user_buf[ep->len], ep->hw_data_buf+64, xferred_bytes[1]);
+      ep->len += xferred_bytes[1];
     }
-    // Flip buf sel for host
-    ep->buf_sel ^= 1u;
-    // end::host_buf_sel_fix[]
-#endif
+  }
 
-    // Get tranferred bytes after adjusted buf sel
-    uint16_t const transferred_bytes = buf_ctrl & USB_BUF_CTRL_LEN_MASK;
-
-    // We are continuing a transfer here. If we are TX, we have successfullly
-    // sent some data can increase the length we have sent
-    if (!ep->rx)
-    {
-        assert(!(buf_ctrl & USB_BUF_CTRL_FULL));
-        pico_trace("tx %d bytes (buf_ctrl 0x%08x)\n", transferred_bytes, buf_ctrl);
-        ep->len += transferred_bytes;
-    }
-    else
-    {
-        // If we are OUT we have recieved some data, so can increase the length
-        // we have recieved AFTER we have copied it to the user buffer at the appropriate
-        // offset
-        pico_trace("rx %d bytes (buf_ctrl 0x%08x)\n", transferred_bytes, buf_ctrl);
-        assert(buf_ctrl & USB_BUF_CTRL_FULL);
-        memcpy(&ep->user_buf[ep->len], ep->hw_data_buf, transferred_bytes);
-        ep->len += transferred_bytes;
-    }
-
-    // Sometimes the host will send less data than we expect...
-    // If this is a short out transfer update the total length of the transfer
-    // to be the current length
-    if ((ep->rx) && (transferred_bytes < ep->wMaxPacketSize))
-    {
-        pico_trace("Short rx transfer\n");
-        // Reduce total length as this is last packet
-        ep->total_len = ep->len;
-    }
+  // Sometimes the host will send less data than we expect...
+  // If this is a short out transfer update the total length of the transfer
+  // to be the current length
+  if ( (ep->rx) && ((xferred_bytes[0] < ep->wMaxPacketSize) || (xferred_bytes[1] && (xferred_bytes[1] < ep->wMaxPacketSize))) )
+  {
+    pico_trace("Short rx transfer\n");
+    // Reduce total length as this is last packet
+    ep->total_len = ep->len;
+  }
 }
 
 // Returns true if transfer is complete
@@ -271,12 +278,11 @@ bool _hw_endpoint_xfer_continue(struct hw_endpoint *ep)
     _hw_endpoint_xfer_sync(ep);
 
     // Now we have synced our state with the hardware. Is there more data to transfer?
-    // Limit by packet size but not less 64 (i.e low speed 8 bytes EP0)
+    // Limit by packet size
     uint16_t remaining_bytes = ep->total_len - ep->len;
-    ep->transfer_size = tu_min16(remaining_bytes, tu_max16(64, ep->wMaxPacketSize));
-#if TUSB_OPT_HOST_ENABLED
-    _hw_endpoint_update_last_buf(ep);
-#endif
+    ep->transfer_size = tu_min16(remaining_bytes, ep->wMaxPacketSize);
+
+    TU_LOG_INT(2, ep->transfer_size);
 
     // Can happen because of programmer error so check for it
     if (ep->len > ep->total_len)
@@ -303,23 +309,4 @@ bool _hw_endpoint_xfer_continue(struct hw_endpoint *ep)
     return false;
 }
 
-void _hw_endpoint_xfer(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len, bool start)
-{
-    // Trace
-    pico_trace("hw_endpoint_xfer ep %d %s", tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
-    pico_trace(" total_len %d, start=%d\n", total_len, start);
-
-    assert(ep->configured);
-
-
-    if (start)
-    {
-        _hw_endpoint_xfer_start(ep, buffer, total_len);
-    }
-    else
-    {
-        _hw_endpoint_xfer_continue(ep);
-    }
-}
-
 #endif
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index 33f3ecd41..d27f4157a 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -17,7 +17,7 @@
 #endif
 
 
-#if false && !defined(NDEBUG)
+#if true || false && !defined(NDEBUG)
 #define pico_trace(format,args...) printf(format, ## args)
 #else
 #define pico_trace(format,...) ((void)0)
@@ -50,6 +50,7 @@ struct hw_endpoint
 
     // Endpoint control register
     io_rw_32 *endpoint_control;
+
     // Buffer control register
     io_rw_32 *buffer_control;
 
@@ -63,8 +64,11 @@ struct hw_endpoint
     bool active;
     uint16_t total_len;
     uint16_t len;
+
     // Amount of data with the hardware
-    uint16_t transfer_size;
+    uint16_t transfer_size; // buf0_len;
+    uint16_t buf_1_len;
+
     // User buffer in main memory
     uint8_t *user_buf;
 
@@ -76,6 +80,7 @@ struct hw_endpoint
 #if TUSB_OPT_HOST_ENABLED
     // Only needed for host mode
     bool last_buf;
+
     // RP2040-E4: HOST BUG. Host will incorrect write status to top half of buffer
     // control register when doing transfers > 1 packet
     uint8_t buf_sel;
@@ -90,11 +95,11 @@ struct hw_endpoint
 void rp2040_usb_init(void);
 
 void hw_endpoint_reset_transfer(struct hw_endpoint *ep);
-void _hw_endpoint_xfer(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len, bool start);
 void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
 void _hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len);
 void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
 bool _hw_endpoint_xfer_continue(struct hw_endpoint *ep);
+
 void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_mask, uint32_t or_mask);
 static inline uint32_t _hw_endpoint_buffer_control_get_value32(struct hw_endpoint *ep) {
     return *ep->buffer_control;
@@ -149,11 +154,11 @@ static inline void print_bufctrl32(uint32_t u32)
   uint16_t u16;
 
   u16 = u32 >> 16;
-  TU_LOG(2, "Buffer Control 1 0x%x: ", u16);
+  TU_LOG(2, "  Buffer Control 1 0x%x: ", u16);
   print_bufctrl16(u16);
 
   u16 = u32 & 0x0000ffff;
-  TU_LOG(2, "Buffer Control 0 0x%x: ", u16);
+  TU_LOG(2, "  Buffer Control 0 0x%x: ", u16);
   print_bufctrl16(u16);
 }
 

From 572d986a0260543ada22592e3f2216a152ac632d Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 17:14:22 +0700
Subject: [PATCH 04/19] improve usbh

---
 examples/host/cdc_msc_hid/src/hid_app.c | 12 +++-
 src/class/hid/hid_host.c                | 10 ----
 src/common/tusb_common.h                |  4 +-
 src/host/usbh.c                         | 78 +++++++++++++------------
 src/host/usbh_control.c                 |  4 +-
 5 files changed, 56 insertions(+), 52 deletions(-)

diff --git a/examples/host/cdc_msc_hid/src/hid_app.c b/examples/host/cdc_msc_hid/src/hid_app.c
index 23ab12404..817646dab 100644
--- a/examples/host/cdc_msc_hid/src/hid_app.c
+++ b/examples/host/cdc_msc_hid/src/hid_app.c
@@ -30,7 +30,8 @@
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
 //--------------------------------------------------------------------+
 
-// If your host terminal support ansi escape code, it can be use to simulate mouse cursor
+// If your host terminal support ansi escape code such as TeraTerm
+// it can be use to simulate mouse cursor movement within terminal
 #define USE_ANSI_ESCAPE   0
 
 #define MAX_REPORT  4
@@ -113,6 +114,13 @@ void tuh_hid_report_received_cb(uint8_t dev_addr, uint8_t instance, uint8_t cons
     return;
   }
 
+  // For complete list of Usage Page & Usage checkout src/class/hid/hid.h. For examples:
+  // - Keyboard                     : Desktop, Keyboard
+  // - Mouse                        : Desktop, Mouse
+  // - Gamepad                      : Desktop, Gamepad
+  // - Consumer Control (Media Key) : Consumer, Consumer Control
+  // - System Control (Power key)   : Desktop, System Control
+  // - Generic (vendor)             : 0xFFxx, xx
   if ( rpt_info->usage_page == HID_USAGE_PAGE_DESKTOP )
   {
     switch (rpt_info->usage)
@@ -164,7 +172,7 @@ static void process_kbd_report(hid_keyboard_report_t const *report)
       }else
       {
         // not existed in previous report means the current key is pressed
-        bool const is_shift =  report->modifier & (KEYBOARD_MODIFIER_LEFTSHIFT | KEYBOARD_MODIFIER_RIGHTSHIFT);
+        bool const is_shift = report->modifier & (KEYBOARD_MODIFIER_LEFTSHIFT | KEYBOARD_MODIFIER_RIGHTSHIFT);
         uint8_t ch = keycode2ascii[report->keycode[i]][is_shift ? 1 : 0];
         putchar(ch);
         if ( ch == '\r' ) putchar('\n'); // added new line for enter key
diff --git a/src/class/hid/hid_host.c b/src/class/hid/hid_host.c
index cde5e23a5..a227c2a86 100644
--- a/src/class/hid/hid_host.c
+++ b/src/class/hid/hid_host.c
@@ -37,16 +37,6 @@
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
 
-/*
- "KEYBOARD"               : in_len=8 , out_len=1, usage_page=0x01, usage=0x06   # Generic Desktop, Keyboard
- "MOUSE"                  : in_len=4 , out_len=0, usage_page=0x01, usage=0x02   # Generic Desktop, Mouse
- "CONSUMER"               : in_len=2 , out_len=0, usage_page=0x0C, usage=0x01   # Consumer, Consumer Control
- "SYS_CONTROL"            : in_len=1 , out_len=0, usage_page=0x01, usage=0x80   # Generic Desktop, Sys Control
- "GAMEPAD"                : in_len=6 , out_len=0, usage_page=0x01, usage=0x05   # Generic Desktop, Game Pad
- "DIGITIZER"              : in_len=5 , out_len=0, usage_page=0x0D, usage=0x02   # Digitizers, Pen
- "XAC_COMPATIBLE_GAMEPAD" : in_len=3 , out_len=0, usage_page=0x01, usage=0x05   # Generic Desktop, Game Pad
- "RAW"                    : in_len=64, out_len=0, usage_page=0xFFAF, usage=0xAF # Vendor 0xFFAF "Adafruit", 0xAF
- */
 typedef struct
 {
   uint8_t itf_num;
diff --git a/src/common/tusb_common.h b/src/common/tusb_common.h
index 889ad7b25..fe5bf5f41 100644
--- a/src/common/tusb_common.h
+++ b/src/common/tusb_common.h
@@ -317,8 +317,8 @@ void tu_print_var(uint8_t const* buf, uint32_t bufsize)
 #define TU_LOG1               tu_printf
 #define TU_LOG1_MEM           tu_print_mem
 #define TU_LOG1_VAR(_x)       tu_print_var((uint8_t const*)(_x), sizeof(*(_x)))
-#define TU_LOG1_INT(_x)       tu_printf(#_x " = %ld\n", (uint32_t) (_x) )
-#define TU_LOG1_HEX(_x)       tu_printf(#_x " = %lX\n", (uint32_t) (_x) )
+#define TU_LOG1_INT(_x)       tu_printf(#_x " = %ld\r\n", (uint32_t) (_x) )
+#define TU_LOG1_HEX(_x)       tu_printf(#_x " = %lX\r\n", (uint32_t) (_x) )
 
 // Log Level 2: Warn
 #if CFG_TUSB_DEBUG >= 2
diff --git a/src/host/usbh.c b/src/host/usbh.c
index 59246a663..81b9e84af 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -795,6 +795,8 @@ static bool enum_get_addr0_device_desc_complete(uint8_t dev_addr, tusb_control_r
     return false;
   }
 
+  TU_ASSERT(tu_desc_type(_usbh_ctrl_buf) == TUSB_DESC_DEVICE);
+
   // Reset device again before Set Address
   TU_LOG2("Port reset \r\n");
 
@@ -938,7 +940,7 @@ static bool enum_get_config_desc_complete(uint8_t dev_addr, tusb_control_request
 
   // Parse configuration & set up drivers
   // Driver open aren't allowed to make any usb transfer yet
-  parse_configuration_descriptor(dev_addr, (tusb_desc_configuration_t*) _usbh_ctrl_buf);
+  TU_ASSERT( parse_configuration_descriptor(dev_addr, (tusb_desc_configuration_t*) _usbh_ctrl_buf) );
 
   TU_LOG2("Set Configuration = %d\r\n", CONFIG_NUM);
   tusb_control_request_t const new_request =
@@ -988,49 +990,53 @@ static bool parse_configuration_descriptor(uint8_t dev_addr, tusb_desc_configura
   // parse each interfaces
   while( p_desc < _usbh_ctrl_buf + desc_cfg->wTotalLength )
   {
-    // skip until we see interface descriptor
-    if ( TUSB_DESC_INTERFACE != tu_desc_type(p_desc) )
-    {
-      p_desc = tu_desc_next(p_desc); // skip the descriptor, increase by the descriptor's length
-    }else
-    {
-      tusb_desc_interface_t const* desc_itf = (tusb_desc_interface_t const*) p_desc;
+    tusb_desc_interface_assoc_t const * desc_itf_assoc = NULL;
 
-      // Check if class is supported
-      uint8_t drv_id;
-      for (drv_id = 0; drv_id < USBH_CLASS_DRIVER_COUNT; drv_id++)
-      {
-        if ( usbh_class_drivers[drv_id].class_code == desc_itf->bInterfaceClass ) break;
-      }
+    // Class will always starts with Interface Association (if any) and then Interface descriptor
+    if ( TUSB_DESC_INTERFACE_ASSOCIATION == tu_desc_type(p_desc) )
+    {
+      desc_itf_assoc = (tusb_desc_interface_assoc_t const *) p_desc;
+      p_desc = tu_desc_next(p_desc); // next to Interface
+    }
 
-      if( drv_id >= USBH_CLASS_DRIVER_COUNT )
+    TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
+
+    tusb_desc_interface_t const* desc_itf = (tusb_desc_interface_t const*) p_desc;
+
+    // Check if class is supported
+    uint8_t drv_id;
+    for (drv_id = 0; drv_id < USBH_CLASS_DRIVER_COUNT; drv_id++)
+    {
+      if ( usbh_class_drivers[drv_id].class_code == desc_itf->bInterfaceClass ) break;
+    }
+
+    if( drv_id >= USBH_CLASS_DRIVER_COUNT )
+    {
+      // skip unsupported class
+      p_desc = tu_desc_next(p_desc);
+    }
+    else
+    {
+      usbh_class_driver_t const * driver = &usbh_class_drivers[drv_id];
+
+      // Interface number must not be used already TODO alternate interface
+      TU_ASSERT( dev->itf2drv[desc_itf->bInterfaceNumber] == 0xff );
+      dev->itf2drv[desc_itf->bInterfaceNumber] = drv_id;
+
+      if (desc_itf->bInterfaceClass == TUSB_CLASS_HUB && dev->hub_addr != 0)
       {
-        // skip unsupported class
+        // TODO Attach hub to Hub is not currently supported
+        // skip this interface
         p_desc = tu_desc_next(p_desc);
       }
       else
       {
-        usbh_class_driver_t const * driver = &usbh_class_drivers[drv_id];
+        TU_LOG2("%s open\r\n", driver->name);
 
-        // Interface number must not be used already TODO alternate interface
-        TU_ASSERT( dev->itf2drv[desc_itf->bInterfaceNumber] == 0xff );
-        dev->itf2drv[desc_itf->bInterfaceNumber] = drv_id;
-
-        if (desc_itf->bInterfaceClass == TUSB_CLASS_HUB && dev->hub_addr != 0)
-        {
-          // TODO Attach hub to Hub is not currently supported
-          // skip this interface
-          p_desc = tu_desc_next(p_desc);
-        }
-        else
-        {
-          TU_LOG2("%s open\r\n", driver->name);
-
-          uint16_t itf_len = 0;
-          TU_ASSERT( driver->open(dev->rhport, dev_addr, desc_itf, &itf_len) );
-          TU_ASSERT( itf_len >= sizeof(tusb_desc_interface_t) );
-          p_desc += itf_len;
-        }
+        uint16_t itf_len = 0;
+        TU_ASSERT( driver->open(dev->rhport, dev_addr, desc_itf, &itf_len) );
+        TU_ASSERT( itf_len >= sizeof(tusb_desc_interface_t) );
+        p_desc += itf_len;
       }
     }
   }
diff --git a/src/host/usbh_control.c b/src/host/usbh_control.c
index aa82f14ba..91dbdfe99 100644
--- a/src/host/usbh_control.c
+++ b/src/host/usbh_control.c
@@ -68,7 +68,7 @@ bool tuh_control_xfer (uint8_t dev_addr, tusb_control_request_t const* request,
   _ctrl_xfer.stage       = STAGE_SETUP;
   _ctrl_xfer.complete_cb = complete_cb;
 
-  TU_LOG2("Send Setup to address %u: ", dev_addr);
+  TU_LOG2("Control Setup (addr = %u): ", dev_addr);
   TU_LOG2_VAR(request);
   TU_LOG2("\r\n");
 
@@ -119,7 +119,7 @@ bool usbh_control_xfer_cb (uint8_t dev_addr, uint8_t ep_addr, xfer_result_t resu
 
         if (request->wLength)
         {
-          TU_LOG2("Control data:\r\n");
+          TU_LOG2("Control data (addr = %u):\r\n", dev_addr);
           TU_LOG2_MEM(_ctrl_xfer.buffer, request->wLength, 2);
         }
 

From 5d6e381ef640fce9f590abe0ce304bf4c9474605 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 17:34:51 +0700
Subject: [PATCH 05/19] refactor rp2040 usb

- make _hw_endpoint_xfer_sync and _hw_endpoint_start_next_buffer private
- drop prefix _ from _hw_endpoint_xfer_continue and
_hw_endpoint_reset_transfer
---
 src/portable/raspberrypi/rp2040/dcd_rp2040.c |  4 +-
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 65 +--------------
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 85 ++++++++++----------
 src/portable/raspberrypi/rp2040/rp2040_usb.h |  6 +-
 4 files changed, 48 insertions(+), 112 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index ccdbb9c01..c755c2e6f 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -201,7 +201,7 @@ static void hw_endpoint_init(uint8_t ep_addr, uint16_t wMaxPacketSize, uint8_t b
 static void hw_endpoint_xfer(uint8_t ep_addr, uint8_t *buffer, uint16_t total_bytes)
 {
     struct hw_endpoint *ep = hw_endpoint_get_by_addr(ep_addr);
-    _hw_endpoint_xfer_start(ep, buffer, total_bytes);
+    hw_endpoint_xfer_start(ep, buffer, total_bytes);
 }
 
 static void hw_handle_buff_status(void)
@@ -221,7 +221,7 @@ static void hw_handle_buff_status(void)
             // IN transfer for even i, OUT transfer for odd i
             struct hw_endpoint *ep = hw_endpoint_get_by_num(i >> 1u, !(i & 1u));
             // Continue xfer
-            bool done = _hw_endpoint_xfer_continue(ep);
+            bool done = hw_endpoint_xfer_continue(ep);
             if (done)
             {
                 // Notify
diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index 561656a10..1ba9725fe 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -123,7 +123,7 @@ static void hw_xfer_complete(struct hw_endpoint *ep, xfer_result_t xfer_result)
 static void _handle_buff_status_bit(uint bit, struct hw_endpoint *ep)
 {
     usb_hw_clear->buf_status = bit;
-    bool done = _hw_endpoint_xfer_continue(ep);
+    bool done = hw_endpoint_xfer_continue(ep);
     if (done)
     {
         hw_xfer_complete(ep, XFER_RESULT_SUCCESS);
@@ -485,65 +485,6 @@ bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const
     return true;
 }
 
-// return true if double buffered
-static bool xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len)
-{
-  // Fill in info now that we're kicking off the hw
-  ep->total_len = total_len;
-  ep->len = 0;
-
-  // Limit by packet size
-  ep->user_buf = buffer;
-
-  // Buffer 0
-  ep->transfer_size = tu_min16(total_len, ep->wMaxPacketSize);
-  total_len -= ep->transfer_size;
-
-  // Buffer 1
-  ep->buf_1_len = tu_min16(total_len, ep->wMaxPacketSize);
-  total_len -= ep->buf_1_len;
-
-  ep->active = true;
-
-  // Write buffer control
-
-  // Buffer 0
-  uint32_t bufctrl = ep->transfer_size  | USB_BUF_CTRL_AVAIL;
-
-  // Copy data to DPB if tx
-  if (!ep->rx)
-  {
-    // Copy data from user buffer to hw buffer
-    memcpy(ep->hw_data_buf, ep->user_buf, ep->transfer_size + ep->buf_1_len);
-
-    // Mark as full
-    bufctrl |= USB_BUF_CTRL_FULL | (ep->buf_1_len ? (USB_BUF_CTRL_FULL << 16) : 0);
-  }
-
-  // PID
-  bufctrl |= ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID;
-  ep->next_pid ^= 1u;
-
-  if (ep->buf_1_len)
-  {
-    bufctrl |= (ep->buf_1_len | USB_BUF_CTRL_AVAIL) << 16;
-    bufctrl |= (ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID) << 16;
-    ep->next_pid ^= 1u;
-  }
-
-  // determine which buffer is last
-  if (total_len == 0)
-  {
-    bufctrl |= USB_BUF_CTRL_LAST << (ep->buf_1_len ? 16 : 0);
-  }
-
-  print_bufctrl32(bufctrl);
-
-  _hw_endpoint_buffer_control_set_value32(ep, bufctrl);
-
-  return ep->buf_1_len > 0;
-}
-
 bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t * buffer, uint16_t buflen)
 {
     (void) rhport;
@@ -567,7 +508,7 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
     // sie ctrl registers. Otherwise interrupt ep registers should
     // already be configured
     if (ep == &epx) {
-        _hw_endpoint_xfer_start(ep, buffer, buflen);
+        hw_endpoint_xfer_start(ep, buffer, buflen);
 
         // That has set up buffer control, endpoint control etc
         // for host we have to initiate the transfer
@@ -581,7 +522,7 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
         usb_hw->sie_ctrl = flags;
     }else
     {
-      _hw_endpoint_xfer_start(ep, buffer, buflen);
+      hw_endpoint_xfer_start(ep, buffer, buflen);
     }
 
     return true;
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 5f61f90c5..293325b8b 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -50,6 +50,13 @@ static inline void _hw_endpoint_update_last_buf(struct hw_endpoint *ep)
 }
 #endif
 
+//--------------------------------------------------------------------+
+//
+//--------------------------------------------------------------------+
+
+void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
+void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
+
 void rp2040_usb_init(void)
 {
     // Reset usb controller
@@ -180,8 +187,7 @@ void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
   _hw_endpoint_buffer_control_set_value32(ep, buf_ctrl);
 }
 
-
-void _hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len)
+void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len)
 {
   _hw_endpoint_lock_update(ep, 1);
   pico_trace("Start transfer of total len %d on ep %d %s\n", total_len, tu_edpt_number(ep->ep_addr),
@@ -205,58 +211,34 @@ void _hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t t
   _hw_endpoint_lock_update(ep, -1);
 }
 
-void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
+static void ep_sync_buf(struct hw_endpoint *ep, uint8_t buf_id)
 {
-  // Update hw endpoint struct with info from hardware
-  // after a buff status interrupt
+  uint32_t buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
+  if (buf_id)  buf_ctrl = buf_ctrl >> 16;
 
-  uint32_t const buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
-  print_bufctrl32(buf_ctrl);
+  uint16_t xferred_bytes = buf_ctrl & USB_BUF_CTRL_LEN_MASK;
 
-  // Transferred bytes for each buffer
-  uint16_t xferred_bytes[2];
-
-  xferred_bytes[0] = buf_ctrl & USB_BUF_CTRL_LEN_MASK;
-
-  // double buffered: take buffer1 into account as well
-  if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
-  {
-    xferred_bytes[1] = (buf_ctrl >> 16) & USB_BUF_CTRL_LEN_MASK;
-  }else
-  {
-    xferred_bytes[1] = 0;
-  }
-
-  TU_LOG_INT(2, xferred_bytes[0]);
-  TU_LOG_INT(2, xferred_bytes[1]);
-
-  // We are continuing a transfer here. If we are TX, we have successfully
-  // sent some data can increase the length we have sent
   if ( !ep->rx )
   {
+    // We are continuing a transfer here. If we are TX, we have successfully
+    // sent some data can increase the length we have sent
     assert(!(buf_ctrl & USB_BUF_CTRL_FULL));
-    ep->len += xferred_bytes[0] + xferred_bytes[1];
-  }
-  else
+
+    ep->len += xferred_bytes;
+  }else
   {
-    // If we are OUT we have recieved some data, so can increase the length
-    // we have recieved AFTER we have copied it to the user buffer at the appropriate offset
+    // If we have received some data, so can increase the length
+    // we have received AFTER we have copied it to the user buffer at the appropriate offset
     assert(buf_ctrl & USB_BUF_CTRL_FULL);
 
-    memcpy(&ep->user_buf[ep->len], ep->hw_data_buf, xferred_bytes[0]);
-    ep->len += xferred_bytes[0];
-
-    if (xferred_bytes[1])
-    {
-      memcpy(&ep->user_buf[ep->len], ep->hw_data_buf+64, xferred_bytes[1]);
-      ep->len += xferred_bytes[1];
-    }
+    memcpy(&ep->user_buf[ep->len], ep->hw_data_buf + buf_id*64, xferred_bytes);
+    ep->len += xferred_bytes;
   }
 
-  // Sometimes the host will send less data than we expect...
-  // If this is a short out transfer update the total length of the transfer
-  // to be the current length
-  if ( (ep->rx) && ((xferred_bytes[0] < ep->wMaxPacketSize) || (xferred_bytes[1] && (xferred_bytes[1] < ep->wMaxPacketSize))) )
+  // Short packet
+  // TODO what if we prepare double buffered but receive short packet on buffer 0 !!!
+  // would the buffer status  or trans complete interrupt is triggered
+  if (xferred_bytes < ep->wMaxPacketSize)
   {
     pico_trace("Short rx transfer\n");
     // Reduce total length as this is last packet
@@ -264,8 +246,23 @@ void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
   }
 }
 
+void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
+{
+  // Update hw endpoint struct with info from hardware
+  // after a buff status interrupt
+
+  // always sync buffer 0
+  ep_sync_buf(ep, 0);
+
+  // sync buffer 1 if double buffered
+  if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
+  {
+    ep_sync_buf(ep, 1);
+  }
+}
+
 // Returns true if transfer is complete
-bool _hw_endpoint_xfer_continue(struct hw_endpoint *ep)
+bool hw_endpoint_xfer_continue(struct hw_endpoint *ep)
 {
     _hw_endpoint_lock_update(ep, 1);
     // Part way through a transfer
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index d27f4157a..b3fcb9417 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -94,11 +94,9 @@ struct hw_endpoint
 
 void rp2040_usb_init(void);
 
+void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len);
+bool hw_endpoint_xfer_continue(struct hw_endpoint *ep);
 void hw_endpoint_reset_transfer(struct hw_endpoint *ep);
-void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
-void _hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len);
-void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
-bool _hw_endpoint_xfer_continue(struct hw_endpoint *ep);
 
 void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_mask, uint32_t or_mask);
 static inline uint32_t _hw_endpoint_buffer_control_get_value32(struct hw_endpoint *ep) {

From 1d48320d8aa85ebeae617be35614cd80011c37f4 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 17:58:29 +0700
Subject: [PATCH 06/19] rename hw endpoint

- total_len to remaining_len
- len to xferred_len
---
 src/portable/raspberrypi/rp2040/dcd_rp2040.c |  2 +-
 src/portable/raspberrypi/rp2040/hcd_rp2040.c |  4 +-
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 78 +++++++++-----------
 src/portable/raspberrypi/rp2040/rp2040_usb.h |  6 +-
 4 files changed, 41 insertions(+), 49 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index c755c2e6f..3f2bf7810 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -225,7 +225,7 @@ static void hw_handle_buff_status(void)
             if (done)
             {
                 // Notify
-                dcd_event_xfer_complete(0, ep->ep_addr, ep->len, XFER_RESULT_SUCCESS, true);
+                dcd_event_xfer_complete(0, ep->ep_addr, ep->xferred_len, XFER_RESULT_SUCCESS, true);
                 hw_endpoint_reset_transfer(ep);
             }
             remaining_buffers &= ~bit;
diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index 1ba9725fe..6a1d7cff2 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -115,7 +115,7 @@ static void hw_xfer_complete(struct hw_endpoint *ep, xfer_result_t xfer_result)
     // Mark transfer as done before we tell the tinyusb stack
     uint8_t dev_addr = ep->dev_addr;
     uint8_t ep_addr = ep->ep_addr;
-    uint xferred_len = ep->len;
+    uint xferred_len = ep->xferred_len;
     hw_endpoint_reset_transfer(ep);
     hcd_event_xfer_complete(dev_addr, ep_addr, xferred_len, xfer_result, true);
 }
@@ -542,7 +542,7 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
     _hw_endpoint_init(ep, dev_addr, 0x00, ep->wMaxPacketSize, 0, 0);
     assert(ep->configured);
 
-    ep->total_len     = 8;
+    ep->remaining_len = 8;
     ep->transfer_size = 8;
     ep->active        = true;
     ep->sent_setup    = true;
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 293325b8b..037b24247 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -43,20 +43,13 @@ static inline void _hw_endpoint_lock_update(struct hw_endpoint *ep, int delta) {
     //  sense to have worker and IRQ on same core, however I think using critsec is about equivalent.
 }
 
-#if TUSB_OPT_HOST_ENABLED
-static inline void _hw_endpoint_update_last_buf(struct hw_endpoint *ep)
-{
-    ep->last_buf = (ep->len + ep->transfer_size == ep->total_len);
-}
-#endif
+void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
+void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
 
 //--------------------------------------------------------------------+
 //
 //--------------------------------------------------------------------+
 
-void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
-void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
-
 void rp2040_usb_init(void)
 {
     // Reset usb controller
@@ -82,8 +75,8 @@ void hw_endpoint_reset_transfer(struct hw_endpoint *ep)
 #if TUSB_OPT_HOST_ENABLED
     ep->sent_setup = false;
 #endif
-    ep->total_len = 0;
-    ep->len = 0;
+    ep->remaining_len = 0;
+    ep->xferred_len = 0;
     ep->transfer_size = 0;
     ep->user_buf = 0;
 }
@@ -118,22 +111,29 @@ void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_m
     *ep->buffer_control = value;
 }
 
+//static void prepare_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
+//{
+//  uint16_t buflen = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
+//
+//
+//}
+
 // Prepare buffer control register value
 void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
 {
-  uint16_t remaining = ep->total_len - ep->len;
   uint32_t ep_ctrl = *ep->endpoint_control;
   uint32_t buf_ctrl;
 
   // Buffer 0
-  ep->transfer_size = tu_min16(remaining, ep->wMaxPacketSize);
-  remaining -= ep->transfer_size;
+  ep->transfer_size = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
+  ep->remaining_len -= ep->transfer_size;
 
   buf_ctrl = ep->transfer_size | USB_BUF_CTRL_AVAIL;
   if ( !ep->rx )
   {
     // Copy data from user buffer to hw buffer
-    memcpy(ep->hw_data_buf, ep->user_buf+ep->len, ep->transfer_size);
+    memcpy(ep->hw_data_buf, ep->user_buf, ep->transfer_size);
+    ep->user_buf += ep->transfer_size;
 
     // Mark as full
     buf_ctrl |= USB_BUF_CTRL_FULL;
@@ -144,8 +144,8 @@ void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
   ep->next_pid ^= 1u;
 
   // Buffer 1
-  ep->buf_1_len = tu_min16(remaining, ep->wMaxPacketSize);
-  remaining -= ep->buf_1_len;
+  ep->buf_1_len = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
+  ep->remaining_len -= ep->buf_1_len;
 
   if (ep->buf_1_len)
   {
@@ -156,7 +156,8 @@ void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
     if ( !ep->rx )
     {
       // Copy data from user buffer to hw buffer
-      memcpy(ep->hw_data_buf+64, ep->user_buf+ep->len+ep->transfer_size, ep->buf_1_len);
+      memcpy(ep->hw_data_buf+64, ep->user_buf, ep->buf_1_len);
+      ep->user_buf += ep->buf_1_len;
     }
 
     // Set endpoint control double buffered bit if needed
@@ -174,7 +175,7 @@ void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
   // Is this the last buffer? Only really matters for host mode. Will trigger
   // the trans complete irq but also stop it polling. We only really care about
   // trans complete for setup packets being sent
-  if (remaining == 0)
+  if (ep->remaining_len == 0)
   {
     buf_ctrl |= USB_BUF_CTRL_LAST << (ep->buf_1_len ? 16 : 0);
   }
@@ -202,16 +203,16 @@ void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t to
   }
 
   // Fill in info now that we're kicking off the hw
-  ep->total_len = total_len;
-  ep->len       = 0;
-  ep->active    = true;
-  ep->user_buf  = buffer;
+  ep->remaining_len = total_len;
+  ep->xferred_len           = 0;
+  ep->active        = true;
+  ep->user_buf      = buffer;
 
   _hw_endpoint_start_next_buffer(ep);
   _hw_endpoint_lock_update(ep, -1);
 }
 
-static void ep_sync_buf(struct hw_endpoint *ep, uint8_t buf_id)
+static void sync_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
 {
   uint32_t buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
   if (buf_id)  buf_ctrl = buf_ctrl >> 16;
@@ -224,15 +225,16 @@ static void ep_sync_buf(struct hw_endpoint *ep, uint8_t buf_id)
     // sent some data can increase the length we have sent
     assert(!(buf_ctrl & USB_BUF_CTRL_FULL));
 
-    ep->len += xferred_bytes;
+    ep->xferred_len += xferred_bytes;
   }else
   {
     // If we have received some data, so can increase the length
     // we have received AFTER we have copied it to the user buffer at the appropriate offset
     assert(buf_ctrl & USB_BUF_CTRL_FULL);
 
-    memcpy(&ep->user_buf[ep->len], ep->hw_data_buf + buf_id*64, xferred_bytes);
-    ep->len += xferred_bytes;
+    memcpy(ep->user_buf, ep->hw_data_buf + buf_id*64, xferred_bytes);
+    ep->xferred_len += xferred_bytes;
+    ep->user_buf += xferred_bytes;
   }
 
   // Short packet
@@ -242,7 +244,7 @@ static void ep_sync_buf(struct hw_endpoint *ep, uint8_t buf_id)
   {
     pico_trace("Short rx transfer\n");
     // Reduce total length as this is last packet
-    ep->total_len = ep->len;
+    ep->remaining_len = 0;
   }
 }
 
@@ -252,12 +254,12 @@ void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
   // after a buff status interrupt
 
   // always sync buffer 0
-  ep_sync_buf(ep, 0);
+  sync_ep_buf(ep, 0);
 
   // sync buffer 1 if double buffered
   if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
   {
-    ep_sync_buf(ep, 1);
+    sync_ep_buf(ep, 1);
   }
 }
 
@@ -275,23 +277,11 @@ bool hw_endpoint_xfer_continue(struct hw_endpoint *ep)
     _hw_endpoint_xfer_sync(ep);
 
     // Now we have synced our state with the hardware. Is there more data to transfer?
-    // Limit by packet size
-    uint16_t remaining_bytes = ep->total_len - ep->len;
-    ep->transfer_size = tu_min16(remaining_bytes, ep->wMaxPacketSize);
-
-    TU_LOG_INT(2, ep->transfer_size);
-
-    // Can happen because of programmer error so check for it
-    if (ep->len > ep->total_len)
-    {
-        panic("Transferred more data than expected");
-    }
-
     // If we are done then notify tinyusb
-    if (ep->len == ep->total_len)
+    if (ep->remaining_len == 0)
     {
         pico_trace("Completed transfer of %d bytes on ep %d %s\n",
-                   ep->len, tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
+                   ep->xferred_len, tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
         // Notify caller we are done so it can notify the tinyusb stack
         _hw_endpoint_lock_update(ep, -1);
         return true;
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index b3fcb9417..d61a5a57f 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -62,10 +62,12 @@ struct hw_endpoint
 
     // Current transfer information
     bool active;
-    uint16_t total_len;
-    uint16_t len;
+    uint16_t remaining_len;
+    uint16_t xferred_len;
 
     // Amount of data with the hardware
+    uint16_t buflen[2];
+
     uint16_t transfer_size; // buf0_len;
     uint16_t buf_1_len;
 

From 93cb2ff4cf5c9b95ed423be6b8dae498868ab435 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 18:14:11 +0700
Subject: [PATCH 07/19] more refactor double buffered rp2040

---
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 179 +++++++++----------
 1 file changed, 86 insertions(+), 93 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 037b24247..38a59d83a 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -52,33 +52,33 @@ void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
 
 void rp2040_usb_init(void)
 {
-    // Reset usb controller
-    reset_block(RESETS_RESET_USBCTRL_BITS);
-    unreset_block_wait(RESETS_RESET_USBCTRL_BITS);
+  // Reset usb controller
+  reset_block(RESETS_RESET_USBCTRL_BITS);
+  unreset_block_wait(RESETS_RESET_USBCTRL_BITS);
 
-    // Clear any previous state just in case
-    memset(usb_hw, 0, sizeof(*usb_hw));
-    memset(usb_dpram, 0, sizeof(*usb_dpram));
+  // Clear any previous state just in case
+  memset(usb_hw, 0, sizeof(*usb_hw));
+  memset(usb_dpram, 0, sizeof(*usb_dpram));
 
-    // Mux the controller to the onboard usb phy
-    usb_hw->muxing = USB_USB_MUXING_TO_PHY_BITS    | USB_USB_MUXING_SOFTCON_BITS;
+  // Mux the controller to the onboard usb phy
+  usb_hw->muxing = USB_USB_MUXING_TO_PHY_BITS    | USB_USB_MUXING_SOFTCON_BITS;
 
-    // Force VBUS detect so the device thinks it is plugged into a host
-    // TODO support VBUs detect
-    usb_hw->pwr    = USB_USB_PWR_VBUS_DETECT_BITS  | USB_USB_PWR_VBUS_DETECT_OVERRIDE_EN_BITS;
+  // Force VBUS detect so the device thinks it is plugged into a host
+  // TODO support VBUs detect
+  usb_hw->pwr    = USB_USB_PWR_VBUS_DETECT_BITS  | USB_USB_PWR_VBUS_DETECT_OVERRIDE_EN_BITS;
 }
 
 void hw_endpoint_reset_transfer(struct hw_endpoint *ep)
 {
-    ep->stalled = false;
-    ep->active = false;
+  ep->stalled = false;
+  ep->active = false;
 #if TUSB_OPT_HOST_ENABLED
-    ep->sent_setup = false;
+  ep->sent_setup = false;
 #endif
-    ep->remaining_len = 0;
-    ep->xferred_len = 0;
-    ep->transfer_size = 0;
-    ep->user_buf = 0;
+  ep->remaining_len = 0;
+  ep->xferred_len = 0;
+  ep->transfer_size = 0;
+  ep->user_buf = 0;
 }
 
 void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_mask, uint32_t or_mask) {
@@ -111,76 +111,69 @@ void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_m
     *ep->buffer_control = value;
 }
 
-//static void prepare_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
-//{
-//  uint16_t buflen = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
-//
-//
-//}
-
-// Prepare buffer control register value
-void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
+static uint32_t compute_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
 {
-  uint32_t ep_ctrl = *ep->endpoint_control;
-  uint32_t buf_ctrl;
+  uint16_t const buflen = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
+  ep->remaining_len -= buflen;
 
-  // Buffer 0
-  ep->transfer_size = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
-  ep->remaining_len -= ep->transfer_size;
-
-  buf_ctrl = ep->transfer_size | USB_BUF_CTRL_AVAIL;
-  if ( !ep->rx )
-  {
-    // Copy data from user buffer to hw buffer
-    memcpy(ep->hw_data_buf, ep->user_buf, ep->transfer_size);
-    ep->user_buf += ep->transfer_size;
-
-    // Mark as full
-    buf_ctrl |= USB_BUF_CTRL_FULL;
-  }
+  uint32_t buf_ctrl = buflen | USB_BUF_CTRL_AVAIL;
 
   // PID
   buf_ctrl |= ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID;
   ep->next_pid ^= 1u;
 
-  // Buffer 1
-  ep->buf_1_len = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
-  ep->remaining_len -= ep->buf_1_len;
-
-  if (ep->buf_1_len)
+  if ( !ep->rx )
   {
-    buf_ctrl |= (ep->buf_1_len | USB_BUF_CTRL_AVAIL) << 16;
-    buf_ctrl |= (ep->next_pid ? USB_BUF_CTRL_DATA1_PID : USB_BUF_CTRL_DATA0_PID) << 16;
-    ep->next_pid ^= 1u;
+    // Copy data from user buffer to hw buffer
+    memcpy(ep->hw_data_buf, ep->user_buf, buflen);
+    ep->user_buf += buflen;
 
-    if ( !ep->rx )
-    {
-      // Copy data from user buffer to hw buffer
-      memcpy(ep->hw_data_buf+64, ep->user_buf, ep->buf_1_len);
-      ep->user_buf += ep->buf_1_len;
-    }
-
-    // Set endpoint control double buffered bit if needed
-    ep_ctrl &= ~EP_CTRL_INTERRUPT_PER_BUFFER;
-    ep_ctrl |= EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER;
-  }else
-  {
-    ep_ctrl &= ~(EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER);
-    ep_ctrl |= EP_CTRL_INTERRUPT_PER_BUFFER;
+    // Mark as full
+    buf_ctrl |= USB_BUF_CTRL_FULL;
   }
 
-  *ep->endpoint_control = ep_ctrl;
-
 #if TUSB_OPT_HOST_ENABLED
   // Is this the last buffer? Only really matters for host mode. Will trigger
   // the trans complete irq but also stop it polling. We only really care about
   // trans complete for setup packets being sent
   if (ep->remaining_len == 0)
   {
-    buf_ctrl |= USB_BUF_CTRL_LAST << (ep->buf_1_len ? 16 : 0);
+    buf_ctrl |= USB_BUF_CTRL_LAST;
   }
 #endif
 
+  if (buf_id) buf_ctrl = buf_ctrl << 16;
+
+  return buf_ctrl;
+}
+
+// Prepare buffer control register value
+void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
+{
+  uint32_t ep_ctrl = *ep->endpoint_control;
+
+  // always compute buffer 0
+  uint32_t buf_ctrl = compute_ep_buf(ep, 0);
+
+  if(ep->remaining_len)
+  {
+    // Use buffer 1 (double buffered) if there is still data
+    // TODO: Isochronous for buffer1 bit-field is different than CBI (control bulk, interrupt)
+
+    buf_ctrl |= compute_ep_buf(ep, 1);
+
+    // Set endpoint control double buffered bit if needed
+    ep_ctrl &= ~EP_CTRL_INTERRUPT_PER_BUFFER;
+    ep_ctrl |= EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER;
+  }else
+  {
+    // Single buffered since 1 is enough
+    ep_ctrl &= ~(EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER);
+    ep_ctrl |= EP_CTRL_INTERRUPT_PER_BUFFER;
+  }
+
+  *ep->endpoint_control = ep_ctrl;
+
   print_bufctrl32(buf_ctrl);
 
   // Finally, write to buffer_control which will trigger the transfer
@@ -266,34 +259,34 @@ void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
 // Returns true if transfer is complete
 bool hw_endpoint_xfer_continue(struct hw_endpoint *ep)
 {
-    _hw_endpoint_lock_update(ep, 1);
-    // Part way through a transfer
-    if (!ep->active)
-    {
-        panic("Can't continue xfer on inactive ep %d %s", tu_edpt_number(ep->ep_addr), ep_dir_string);
-    }
+  _hw_endpoint_lock_update(ep, 1);
+  // Part way through a transfer
+  if (!ep->active)
+  {
+    panic("Can't continue xfer on inactive ep %d %s", tu_edpt_number(ep->ep_addr), ep_dir_string);
+  }
 
-    // Update EP struct from hardware state
-    _hw_endpoint_xfer_sync(ep);
-
-    // Now we have synced our state with the hardware. Is there more data to transfer?
-    // If we are done then notify tinyusb
-    if (ep->remaining_len == 0)
-    {
-        pico_trace("Completed transfer of %d bytes on ep %d %s\n",
-                   ep->xferred_len, tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
-        // Notify caller we are done so it can notify the tinyusb stack
-        _hw_endpoint_lock_update(ep, -1);
-        return true;
-    }
-    else
-    {
-        _hw_endpoint_start_next_buffer(ep);
-    }
+  // Update EP struct from hardware state
+  _hw_endpoint_xfer_sync(ep);
 
+  // Now we have synced our state with the hardware. Is there more data to transfer?
+  // If we are done then notify tinyusb
+  if (ep->remaining_len == 0)
+  {
+    pico_trace("Completed transfer of %d bytes on ep %d %s\n",
+               ep->xferred_len, tu_edpt_number(ep->ep_addr), ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
+    // Notify caller we are done so it can notify the tinyusb stack
     _hw_endpoint_lock_update(ep, -1);
-    // More work to do
-    return false;
+    return true;
+  }
+  else
+  {
+    _hw_endpoint_start_next_buffer(ep);
+  }
+
+  _hw_endpoint_lock_update(ep, -1);
+  // More work to do
+  return false;
 }
 
 #endif

From 66c8a13f137d54a2c140d04310cd4b7adba50401 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 18:26:41 +0700
Subject: [PATCH 08/19] remove unused variable in hw endpoint

last_buf, buf_sel, transfer_size
---
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 18 ++++++++--------
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 22 ++++++++++----------
 src/portable/raspberrypi/rp2040/rp2040_usb.h | 12 -----------
 3 files changed, 20 insertions(+), 32 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index 6a1d7cff2..0bbd7e7c2 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ * Copyright (c) 2021 Ha Thach (tinyusb.org) for Double Buffered
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -220,6 +221,14 @@ static void hcd_rp2040_irq(void)
         usb_hw_clear->sie_status = USB_SIE_STATUS_SPEED_BITS;
     }
 
+    if (status & USB_INTS_BUFF_STATUS_BITS)
+    {
+        handled |= USB_INTS_BUFF_STATUS_BITS;
+        TU_LOG(2, "Buffer complete\n");
+        // print_bufctrl32(*epx.buffer_control);
+        hw_handle_buff_status();
+    }
+
     if (status & USB_INTS_TRANS_COMPLETE_BITS)
     {
         handled |= USB_INTS_TRANS_COMPLETE_BITS;
@@ -228,14 +237,6 @@ static void hcd_rp2040_irq(void)
         hw_trans_complete();
     }
 
-    if (status & USB_INTS_BUFF_STATUS_BITS)
-    {
-        handled |= USB_INTS_BUFF_STATUS_BITS;
-        TU_LOG(2, "Buffer complete\n");
-        print_bufctrl32(*epx.buffer_control);
-        hw_handle_buff_status();
-    }
-
     if (status & USB_INTS_STALL_BITS)
     {
         // We have rx'd a stall from the device
@@ -543,7 +544,6 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
     assert(ep->configured);
 
     ep->remaining_len = 8;
-    ep->transfer_size = 8;
     ep->active        = true;
     ep->sent_setup    = true;
 
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 38a59d83a..26c6e8b13 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ * Copyright (c) 2021 Ha Thach (tinyusb.org) for Double Buffered
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -43,8 +44,8 @@ static inline void _hw_endpoint_lock_update(struct hw_endpoint *ep, int delta) {
     //  sense to have worker and IRQ on same core, however I think using critsec is about equivalent.
 }
 
-void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
-void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
+static void _hw_endpoint_xfer_sync(struct hw_endpoint *ep);
+static void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep);
 
 //--------------------------------------------------------------------+
 //
@@ -77,7 +78,6 @@ void hw_endpoint_reset_transfer(struct hw_endpoint *ep)
 #endif
   ep->remaining_len = 0;
   ep->xferred_len = 0;
-  ep->transfer_size = 0;
   ep->user_buf = 0;
 }
 
@@ -111,7 +111,7 @@ void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_m
     *ep->buffer_control = value;
 }
 
-static uint32_t compute_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
+static uint32_t compute_buffer_control(struct hw_endpoint *ep, uint8_t buf_id)
 {
   uint16_t const buflen = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
   ep->remaining_len -= buflen;
@@ -148,19 +148,19 @@ static uint32_t compute_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
 }
 
 // Prepare buffer control register value
-void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
+static void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
 {
   uint32_t ep_ctrl = *ep->endpoint_control;
 
   // always compute buffer 0
-  uint32_t buf_ctrl = compute_ep_buf(ep, 0);
+  uint32_t buf_ctrl = compute_buffer_control(ep, 0);
 
   if(ep->remaining_len)
   {
     // Use buffer 1 (double buffered) if there is still data
     // TODO: Isochronous for buffer1 bit-field is different than CBI (control bulk, interrupt)
 
-    buf_ctrl |= compute_ep_buf(ep, 1);
+    buf_ctrl |= compute_buffer_control(ep, 1);
 
     // Set endpoint control double buffered bit if needed
     ep_ctrl &= ~EP_CTRL_INTERRUPT_PER_BUFFER;
@@ -205,7 +205,7 @@ void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t to
   _hw_endpoint_lock_update(ep, -1);
 }
 
-static void sync_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
+static void sync_ep_buffer(struct hw_endpoint *ep, uint8_t buf_id)
 {
   uint32_t buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
   if (buf_id)  buf_ctrl = buf_ctrl >> 16;
@@ -241,18 +241,18 @@ static void sync_ep_buf(struct hw_endpoint *ep, uint8_t buf_id)
   }
 }
 
-void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
+static void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
 {
   // Update hw endpoint struct with info from hardware
   // after a buff status interrupt
 
   // always sync buffer 0
-  sync_ep_buf(ep, 0);
+  sync_ep_buffer(ep, 0);
 
   // sync buffer 1 if double buffered
   if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
   {
-    sync_ep_buf(ep, 1);
+    sync_ep_buffer(ep, 1);
   }
 }
 
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index d61a5a57f..ada1dd750 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -65,12 +65,6 @@ struct hw_endpoint
     uint16_t remaining_len;
     uint16_t xferred_len;
 
-    // Amount of data with the hardware
-    uint16_t buflen[2];
-
-    uint16_t transfer_size; // buf0_len;
-    uint16_t buf_1_len;
-
     // User buffer in main memory
     uint8_t *user_buf;
 
@@ -80,12 +74,6 @@ struct hw_endpoint
     uint8_t transfer_type;
     
 #if TUSB_OPT_HOST_ENABLED
-    // Only needed for host mode
-    bool last_buf;
-
-    // RP2040-E4: HOST BUG. Host will incorrect write status to top half of buffer
-    // control register when doing transfers > 1 packet
-    uint8_t buf_sel;
     // Only needed for host
     uint8_t dev_addr;
     bool sent_setup;

From a6d22f5a6879388e657987378cecea827794ad1e Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 18:39:28 +0700
Subject: [PATCH 09/19] replace pico_warn by log level 1

---
 src/portable/raspberrypi/rp2040/rp2040_usb.c |  2 +-
 src/portable/raspberrypi/rp2040/rp2040_usb.h | 24 +++++++++++---------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 26c6e8b13..cb46ad1b9 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -189,7 +189,7 @@ void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t to
   if ( ep->active )
   {
     // TODO: Is this acceptable for interrupt packets?
-    pico_warn("WARN: starting new transfer on already active ep %d %s\n", tu_edpt_number(ep->ep_addr),
+    TU_LOG(1, "WARN: starting new transfer on already active ep %d %s\n", tu_edpt_number(ep->ep_addr),
               ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
 
     hw_endpoint_reset_transfer(ep);
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index ada1dd750..278ba59ec 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -29,12 +29,6 @@
 #define pico_info(format,...) ((void)0)
 #endif
 
-#if false && !defined(NDEBUG)
-#define pico_warn(format,args...) printf(format, ## args)
-#else
-#define pico_warn(format,...) ((void)0)
-#endif
-
 // Hardware information per endpoint
 struct hw_endpoint
 {
@@ -127,13 +121,14 @@ typedef union TU_ATTR_PACKED
 
 TU_VERIFY_STATIC(sizeof(rp2040_buffer_control_t) == 2, "size is not correct");
 
-static inline void print_bufctrl16(uint32_t __unused u16)
+#if CFG_TUSB_DEBUG >= 3
+static inline void print_bufctrl16(uint32_t u16)
 {
-  rp2040_buffer_control_t __unused bufctrl = {
+  rp2040_buffer_control_t bufctrl = {
       .u16 = u16
   };
 
-  TU_LOG(2, "len = %u, available = %u, stall = %u, reset = %u, toggle = %u, last = %u, full = %u\r\n",
+  TU_LOG(3, "len = %u, available = %u, stall = %u, reset = %u, toggle = %u, last = %u, full = %u\r\n",
          bufctrl.xfer_len, bufctrl.available, bufctrl.stall, bufctrl.reset_bufsel, bufctrl.data_toggle, bufctrl.last_buf, bufctrl.full);
 }
 
@@ -142,12 +137,19 @@ static inline void print_bufctrl32(uint32_t u32)
   uint16_t u16;
 
   u16 = u32 >> 16;
-  TU_LOG(2, "  Buffer Control 1 0x%x: ", u16);
+  TU_LOG(3, "  Buffer Control 1 0x%x: ", u16);
   print_bufctrl16(u16);
 
   u16 = u32 & 0x0000ffff;
-  TU_LOG(2, "  Buffer Control 0 0x%x: ", u16);
+  TU_LOG(3, "  Buffer Control 0 0x%x: ", u16);
   print_bufctrl16(u16);
 }
 
+#else
+
+#define print_bufctrl16(u16)
+#define print_bufctrl32(u32)
+
+#endif
+
 #endif

From b39faa15effec35dceb95655b0db75c3fe564f3d Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 18:44:08 +0700
Subject: [PATCH 10/19] map pico_info to log2, pico_trace to log3

---
 src/portable/raspberrypi/rp2040/rp2040_usb.h | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index 278ba59ec..4c24b8dbe 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -17,17 +17,8 @@
 #endif
 
 
-#if true || false && !defined(NDEBUG)
-#define pico_trace(format,args...) printf(format, ## args)
-#else
-#define pico_trace(format,...) ((void)0)
-#endif
-
-#if false && !defined(NDEBUG)
-#define pico_info(format,args...) printf(format, ## args)
-#else
-#define pico_info(format,...) ((void)0)
-#endif
+#define pico_info(...)  TU_LOG(2, __VA_ARGS__)
+#define pico_trace(...) TU_LOG(3, __VA_ARGS__)
 
 // Hardware information per endpoint
 struct hw_endpoint

From dfe5a727c6b236c1b05b5447cdf0535545a6d32e Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 18:53:56 +0700
Subject: [PATCH 11/19] log clean up

---
 src/class/hid/hid_host.c                     | 6 +++---
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 8 +++-----
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/class/hid/hid_host.c b/src/class/hid/hid_host.c
index a227c2a86..7444c10fe 100644
--- a/src/class/hid/hid_host.c
+++ b/src/class/hid/hid_host.c
@@ -442,9 +442,9 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info_arr,
 
     uint8_t const data8 = desc_report[0];
 
-    TU_LOG2("tag = %d, type = %d, size = %d, data = ", tag, type, size);
-    for(uint32_t i=0; i<size; i++) TU_LOG2("%02X ", desc_report[i]);
-    TU_LOG2("\r\n");
+    TU_LOG(3, "tag = %d, type = %d, size = %d, data = ", tag, type, size);
+    for(uint32_t i=0; i<size; i++) TU_LOG(3, "%02X ", desc_report[i]);
+    TU_LOG(3, "\r\n");
 
     switch(type)
     {
diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index 0bbd7e7c2..c145082f2 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -146,15 +146,13 @@ static void hw_handle_buff_status(void)
         uint32_t ep_ctrl = *ep->endpoint_control;
         if (ep_ctrl & EP_CTRL_DOUBLE_BUFFERED_BITS)
         {
-          TU_LOG(2, "Double Buffered ");
+          TU_LOG(3, "Double Buffered: ");
         }else
         {
-          TU_LOG(2, "Single Buffered ");
+          TU_LOG(3, "Single Buffered: ");
         }
 
-        if (ep_ctrl & EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER) TU_LOG(2, "Interrupt per double ");
-        if (ep_ctrl & EP_CTRL_INTERRUPT_PER_BUFFER) TU_LOG(2, "Interrupt per single ");
-        TU_LOG_HEX(2, ep_ctrl);
+        TU_LOG_HEX(3, ep_ctrl);
 
         _handle_buff_status_bit(bit, ep);
     }

From 910e11a8aba7328a3cb61ecf8ac5a10f8a525377 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Fri, 11 Jun 2021 19:04:16 +0700
Subject: [PATCH 12/19] fix ci build

---
 src/host/usbh.c                              | 7 ++++---
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 1 -
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/host/usbh.c b/src/host/usbh.c
index 81b9e84af..203f9fd54 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -990,13 +990,14 @@ static bool parse_configuration_descriptor(uint8_t dev_addr, tusb_desc_configura
   // parse each interfaces
   while( p_desc < _usbh_ctrl_buf + desc_cfg->wTotalLength )
   {
-    tusb_desc_interface_assoc_t const * desc_itf_assoc = NULL;
+    // TODO Do we need to use IAD
+    // tusb_desc_interface_assoc_t const * desc_itf_assoc = NULL;
 
     // Class will always starts with Interface Association (if any) and then Interface descriptor
     if ( TUSB_DESC_INTERFACE_ASSOCIATION == tu_desc_type(p_desc) )
     {
-      desc_itf_assoc = (tusb_desc_interface_assoc_t const *) p_desc;
-      p_desc = tu_desc_next(p_desc); // next to Interface
+      // desc_itf_assoc = (tusb_desc_interface_assoc_t const *) p_desc;
+      p_desc = tu_desc_next(p_desc);
     }
 
     TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index c145082f2..ab8639861 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -151,7 +151,6 @@ static void hw_handle_buff_status(void)
         {
           TU_LOG(3, "Single Buffered: ");
         }
-
         TU_LOG_HEX(3, ep_ctrl);
 
         _handle_buff_status_bit(bit, ep);

From a4ad064e638679a7c8759a2c30ed555bd93e524b Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Sat, 12 Jun 2021 14:20:09 +0700
Subject: [PATCH 13/19] increase example CFG_TUH_HID from 2 to 4

---
 examples/host/cdc_msc_hid/src/tusb_config.h | 2 +-
 src/common/tusb_verify.h                    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/host/cdc_msc_hid/src/tusb_config.h b/examples/host/cdc_msc_hid/src/tusb_config.h
index 8253964c0..531bb2c30 100644
--- a/examples/host/cdc_msc_hid/src/tusb_config.h
+++ b/examples/host/cdc_msc_hid/src/tusb_config.h
@@ -76,7 +76,7 @@
 
 #define CFG_TUH_HUB                 1
 #define CFG_TUH_CDC                 1
-#define CFG_TUH_HID                 2
+#define CFG_TUH_HID                 4
 #define CFG_TUH_MSC                 1
 #define CFG_TUH_VENDOR              0
 
diff --git a/src/common/tusb_verify.h b/src/common/tusb_verify.h
index 542809899..56ba8bcd1 100644
--- a/src/common/tusb_verify.h
+++ b/src/common/tusb_verify.h
@@ -75,7 +75,7 @@
 #if CFG_TUSB_DEBUG
   #include <stdio.h>
   #define _MESS_ERR(_err)   tu_printf("%s %d: failed, error = %s\r\n", __func__, __LINE__, tusb_strerr[_err])
-  #define _MESS_FAILED()    tu_printf("%s %d: assert failed\r\n", __func__, __LINE__)
+  #define _MESS_FAILED()    tu_printf("%s %d: ASSERT FAILED\r\n", __func__, __LINE__)
 #else
   #define _MESS_ERR(_err) do {} while (0)
   #define _MESS_FAILED() do {} while (0)

From 289ccf3c938c8f2be0edf2a2c8a18c68e39880c0 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Sun, 13 Jun 2021 13:18:32 +0700
Subject: [PATCH 14/19] remove dev_ep_map

---
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 49 ++++++--------------
 1 file changed, 13 insertions(+), 36 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index ab8639861..42d0839f6 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -59,44 +59,24 @@ static struct hw_endpoint ep_pool[1 + PICO_USB_HOST_INTERRUPT_ENDPOINTS];
 #define usb_hw_set   hw_set_alias(usb_hw)
 #define usb_hw_clear hw_clear_alias(usb_hw)
 
-// todo still a bit wasteful
-// top bit set if valid
-uint8_t dev_ep_map[CFG_TUSB_HOST_DEVICE_MAX][1 + PICO_USB_HOST_INTERRUPT_ENDPOINTS][2];
-
 // Flags we set by default in sie_ctrl (we add other bits on top)
 enum {
-  sie_ctrl_base = USB_SIE_CTRL_SOF_EN_BITS        |
-                  USB_SIE_CTRL_KEEP_ALIVE_EN_BITS |
-                  USB_SIE_CTRL_PULLDOWN_EN_BITS   |
-                  USB_SIE_CTRL_EP0_INT_1BUF_BITS
+  SIE_CTRL_BASE = USB_SIE_CTRL_SOF_EN_BITS        | USB_SIE_CTRL_KEEP_ALIVE_EN_BITS |
+                  USB_SIE_CTRL_PULLDOWN_EN_BITS   | USB_SIE_CTRL_EP0_INT_1BUF_BITS
 };
 
 static struct hw_endpoint *get_dev_ep(uint8_t dev_addr, uint8_t ep_addr)
 {
-    uint8_t num = tu_edpt_number(ep_addr);
-    if (num == 0) {
-        return &epx;
-    }
-    uint8_t in = (ep_addr & TUSB_DIR_IN_MASK) ? 1 : 0;
-    uint mapping = dev_ep_map[dev_addr-1][num][in];
-    pico_trace("Get dev addr %d ep %d = %d\n", dev_addr, ep_addr, mapping);
-    return mapping >= 128 ? ep_pool + (mapping & 0x7fu) : NULL;
-}
+  uint8_t num = tu_edpt_number(ep_addr);
+  if ( num == 0 ) return &epx;
 
-static void set_dev_ep(uint8_t dev_addr, uint8_t ep_addr, struct hw_endpoint *ep)
-{
-    uint8_t num = tu_edpt_number(ep_addr);
-    uint8_t in = (uint8_t) tu_edpt_dir(ep_addr);
+  for ( uint32_t i = 1; i < TU_ARRAY_SIZE(ep_pool); i++ )
+  {
+    struct hw_endpoint *ep = &ep_pool[i];
+    if ( ep->configured && (ep->dev_addr == dev_addr) && (ep->ep_addr == ep_addr) ) return ep;
+  }
 
-    uint32_t index = ep - ep_pool;
-    hard_assert(index < TU_ARRAY_SIZE(ep_pool));
-
-    // todo revisit why dev_addr can be 0 here
-    if (dev_addr) {
-        dev_ep_map[dev_addr-1][num][in] = 128u | index;
-    }
-
-    pico_trace("Set dev addr %d ep %d = %d\n", dev_addr, ep_addr, index);
+  return NULL;
 }
 
 static inline uint8_t dev_speed(void)
@@ -387,7 +367,7 @@ bool hcd_init(uint8_t rhport)
 
     // Enable in host mode with SOF / Keep alive on
     usb_hw->main_ctrl = USB_MAIN_CTRL_CONTROLLER_EN_BITS | USB_MAIN_CTRL_HOST_NDEVICE_BITS;
-    usb_hw->sie_ctrl = sie_ctrl_base;
+    usb_hw->sie_ctrl = SIE_CTRL_BASE;
     usb_hw->inte = USB_INTE_BUFF_STATUS_BITS      | 
                    USB_INTE_HOST_CONN_DIS_BITS    | 
                    USB_INTE_HOST_RESUME_BITS      | 
@@ -477,9 +457,6 @@ bool hcd_edpt_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint_t const
         ep_desc->bmAttributes.xfer,
         ep_desc->bInterval);
 
-    // Map this struct to ep@device address
-    set_dev_ep(dev_addr, ep_desc->bEndpointAddress, ep);
-
     return true;
 }
 
@@ -512,7 +489,7 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
         // for host we have to initiate the transfer
         usb_hw->dev_addr_ctrl = dev_addr | (ep_num << USB_ADDR_ENDP_ENDPOINT_LSB);
 
-        uint32_t flags = USB_SIE_CTRL_START_TRANS_BITS | sie_ctrl_base |
+        uint32_t flags = USB_SIE_CTRL_START_TRANS_BITS | SIE_CTRL_BASE |
                          (ep_dir ? USB_SIE_CTRL_RECEIVE_DATA_BITS : USB_SIE_CTRL_SEND_DATA_BITS);
         // Set pre if we are a low speed device on full speed hub
         flags |= need_pre(dev_addr) ? USB_SIE_CTRL_PREAMBLE_EN_BITS : 0;
@@ -548,7 +525,7 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
     usb_hw->dev_addr_ctrl = dev_addr;
 
     // Set pre if we are a low speed device on full speed hub
-    uint32_t const flags = sie_ctrl_base | USB_SIE_CTRL_SEND_SETUP_BITS | USB_SIE_CTRL_START_TRANS_BITS |
+    uint32_t const flags = SIE_CTRL_BASE | USB_SIE_CTRL_SEND_SETUP_BITS | USB_SIE_CTRL_START_TRANS_BITS |
                            (need_pre(dev_addr) ? USB_SIE_CTRL_PREAMBLE_EN_BITS : 0);
 
     usb_hw->sie_ctrl = flags;

From 1af64f9729f743f4fc9d8686af239c65f689630f Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Sun, 13 Jun 2021 15:27:20 +0700
Subject: [PATCH 15/19] remove sent_setup from hw endpoint

---
 src/portable/raspberrypi/rp2040/hcd_rp2040.c | 34 +++++++++++---------
 src/portable/raspberrypi/rp2040/rp2040_usb.c |  3 --
 src/portable/raspberrypi/rp2040/rp2040_usb.h |  3 +-
 3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/hcd_rp2040.c b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
index 42d0839f6..40a0805c6 100644
--- a/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/hcd_rp2040.c
@@ -161,19 +161,19 @@ static void hw_handle_buff_status(void)
 
 static void hw_trans_complete(void)
 {
-    struct hw_endpoint *ep = &epx;
-    assert(ep->active);
+  struct hw_endpoint *ep = &epx;
+  assert(ep->active);
 
-    if (ep->sent_setup)
-    {
-        pico_trace("Sent setup packet\n");
-        hw_xfer_complete(ep, XFER_RESULT_SUCCESS);
-    }
-    else
-    {
-        // Don't care. Will handle this in buff status
-        return;
-    }
+  if (usb_hw->sie_ctrl & USB_SIE_CTRL_SEND_SETUP_BITS)
+  {
+    pico_trace("Sent setup packet\n");
+    hw_xfer_complete(ep, XFER_RESULT_SUCCESS);
+  }
+  else
+  {
+    // Don't care. Will handle this in buff status
+    return;
+  }
 }
 
 static void hcd_rp2040_irq(void)
@@ -473,10 +473,13 @@ bool hcd_edpt_xfer(uint8_t rhport, uint8_t dev_addr, uint8_t ep_addr, uint8_t *
     struct hw_endpoint *ep = get_dev_ep(dev_addr, ep_addr);
     assert(ep);
 
-    if (ep_addr != ep->ep_addr)
+    // Control endpoint can change direction 0x00 <-> 0x80
+    if ( ep_addr != ep->ep_addr )
     {
-        // Direction has flipped on endpoint control so re init it but with same properties
-        _hw_endpoint_init(ep, dev_addr, ep_addr, ep->wMaxPacketSize, ep->transfer_type, 0);
+      assert(ep_num == 0);
+
+      // Direction has flipped on endpoint control so re init it but with same properties
+      _hw_endpoint_init(ep, dev_addr, ep_addr, ep->wMaxPacketSize, ep->transfer_type, 0);
     }
 
     // If a normal transfer (non-interrupt) then initiate using
@@ -519,7 +522,6 @@ bool hcd_setup_send(uint8_t rhport, uint8_t dev_addr, uint8_t const setup_packet
 
     ep->remaining_len = 8;
     ep->active        = true;
-    ep->sent_setup    = true;
 
     // Set device address
     usb_hw->dev_addr_ctrl = dev_addr;
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index cb46ad1b9..7430881e0 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -73,9 +73,6 @@ void hw_endpoint_reset_transfer(struct hw_endpoint *ep)
 {
   ep->stalled = false;
   ep->active = false;
-#if TUSB_OPT_HOST_ENABLED
-  ep->sent_setup = false;
-#endif
   ep->remaining_len = 0;
   ep->xferred_len = 0;
   ep->user_buf = 0;
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index 4c24b8dbe..4c787f496 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -55,13 +55,14 @@ struct hw_endpoint
 
     // Data needed from EP descriptor
     uint16_t wMaxPacketSize;
+
     // Interrupt, bulk, etc
     uint8_t transfer_type;
     
 #if TUSB_OPT_HOST_ENABLED
     // Only needed for host
     uint8_t dev_addr;
-    bool sent_setup;
+
     // If interrupt endpoint
     uint8_t interrupt_num;
 #endif

From bd039c8d37d7df05da992eb8afdcb31f782e1f23 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Sun, 13 Jun 2021 16:16:25 +0700
Subject: [PATCH 16/19] fix build with log for device

---
 src/portable/raspberrypi/rp2040/dcd_rp2040.c | 35 +++++---------------
 src/portable/raspberrypi/rp2040/rp2040_usb.c |  2 +-
 2 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index 3f2bf7810..63e129e53 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -69,6 +69,7 @@ static void _hw_endpoint_alloc(struct hw_endpoint *ep)
     // Assumes single buffered for now
     ep->hw_data_buf = next_buffer_ptr;
     next_buffer_ptr += size;
+
     // Bits 0-5 are ignored by the controller so make sure these are 0
     if ((uintptr_t)next_buffer_ptr & 0b111111u)
     {
@@ -87,8 +88,8 @@ static void _hw_endpoint_alloc(struct hw_endpoint *ep)
                 size,
                 dpram_offset,
                 ep->hw_data_buf,
-                ep->num,
-                ep_dir_string[ep->in]);
+                tu_edpt_number(ep->ep_addr),
+                ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
 
     // Fill in endpoint control register with buffer offset
     uint32_t reg =  EP_CTRL_ENABLE_BITS
@@ -103,28 +104,15 @@ static void _hw_endpoint_init(struct hw_endpoint *ep, uint8_t ep_addr, uint16_t
 {
     const uint8_t num = tu_edpt_number(ep_addr);
     const tusb_dir_t dir = tu_edpt_dir(ep_addr);
+
     ep->ep_addr = ep_addr;
+
     // For device, IN is a tx transfer and OUT is an rx transfer
     ep->rx = (dir == TUSB_DIR_OUT);
+
     // Response to a setup packet on EP0 starts with pid of 1
     ep->next_pid = num == 0 ? 1u : 0u;
 
-    // Add some checks around the max packet size
-    if (transfer_type == TUSB_XFER_ISOCHRONOUS)
-    {
-        if (wMaxPacketSize > USB_MAX_ISO_PACKET_SIZE)
-        {
-            panic("Isochronous wMaxPacketSize %d too large", wMaxPacketSize);
-        }
-    }
-    else
-    {
-        if (wMaxPacketSize > USB_MAX_PACKET_SIZE)
-        {
-            panic("Isochronous wMaxPacketSize %d too large", wMaxPacketSize);
-        }
-    }
-
     ep->wMaxPacketSize = wMaxPacketSize;
     ep->transfer_type = transfer_type;
 
@@ -339,10 +327,7 @@ static void dcd_rp2040_irq(void)
 
 #if TUD_OPT_RP2040_USB_DEVICE_ENUMERATION_FIX
         // Only run enumeration walk-around if pull up is enabled
-        if ( usb_hw->sie_ctrl & USB_SIE_CTRL_PULLUP_EN_BITS )
-        {
-          rp2040_usb_device_enumeration_fix();
-        }
+        if ( usb_hw->sie_ctrl & USB_SIE_CTRL_PULLUP_EN_BITS ) rp2040_usb_device_enumeration_fix();
 #endif
     }
 
@@ -402,9 +387,9 @@ void dcd_init (uint8_t rhport)
 
     // EP0 always exists so init it now
     // EP0 OUT
-    hw_endpoint_init(0x0, 64, 0);
+    hw_endpoint_init(0x0, 64, TUSB_XFER_CONTROL);
     // EP0 IN
-    hw_endpoint_init(0x80, 64, 0);
+    hw_endpoint_init(0x80, 64, TUSB_XFER_CONTROL);
 
     // Initializes the USB peripheral for device mode and enables it.
     // Don't need to enable the pull up here. Force VBUS
@@ -495,7 +480,6 @@ bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
 bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes)
 {
     assert(rhport == 0);
-    // True means start new xfer
     hw_endpoint_xfer(ep_addr, buffer, total_bytes);
     return true;
 }
@@ -519,7 +503,6 @@ void dcd_edpt_close (uint8_t rhport, uint8_t ep_addr)
 {
     // usbd.c says: In progress transfers on this EP may be delivered after this call
     pico_trace("dcd_edpt_close %d %02x\n", rhport, ep_addr);
-
 }
 
 void dcd_int_handler(uint8_t rhport)
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 7430881e0..de3a83be9 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -194,7 +194,7 @@ void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t to
 
   // Fill in info now that we're kicking off the hw
   ep->remaining_len = total_len;
-  ep->xferred_len           = 0;
+  ep->xferred_len   = 0;
   ep->active        = true;
   ep->user_buf      = buffer;
 

From f38c460433abc0c557f2035c7205b4f36bcbc677 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Sun, 13 Jun 2021 17:19:14 +0700
Subject: [PATCH 17/19] fix ep tx with double buffered

---
 src/common/tusb_common.h                     |  2 +-
 src/portable/raspberrypi/rp2040/dcd_rp2040.c | 48 ++++++++------------
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 11 ++---
 3 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/src/common/tusb_common.h b/src/common/tusb_common.h
index fe5bf5f41..8490daad7 100644
--- a/src/common/tusb_common.h
+++ b/src/common/tusb_common.h
@@ -123,7 +123,7 @@ TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_align4k (uint32_t value) { retur
 TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_offset4k(uint32_t value) { return (value & 0xFFFUL); }
 
 //------------- Mathematics -------------//
-TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_abs(int32_t value) { return (uint32_t)((value < 0) ? (-value) : value); }
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tu_div_ceil(uint32_t v, uint32_t d) { return (v + d -1)/d; }
 
 /// inclusive range checking TODO remove
 TU_ATTR_ALWAYS_INLINE static inline bool tu_within(uint32_t lower, uint32_t value, uint32_t upper)
diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index 63e129e53..4f70d60cc 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -64,40 +64,30 @@ static struct hw_endpoint *hw_endpoint_get_by_addr(uint8_t ep_addr)
 
 static void _hw_endpoint_alloc(struct hw_endpoint *ep)
 {
-    uint16_t size = tu_min16(64, ep->wMaxPacketSize);
+  // size must be multiple of 64
+  uint16_t size = tu_div_ceil(ep->wMaxPacketSize, 64) * 64u;
 
-    // Assumes single buffered for now
-    ep->hw_data_buf = next_buffer_ptr;
-    next_buffer_ptr += size;
+  // double buffered for non-ISO endpoint
+  if ( ep->transfer_type != TUSB_XFER_ISOCHRONOUS ) size *= 2u;
 
-    // Bits 0-5 are ignored by the controller so make sure these are 0
-    if ((uintptr_t)next_buffer_ptr & 0b111111u)
-    {
-        // Round up to the next 64
-        uint32_t fixptr = (uintptr_t)next_buffer_ptr;
-        fixptr &= ~0b111111u;
-        fixptr += 64;
-        pico_info("Rounding non 64 byte boundary buffer up from %x to %x\n", (uintptr_t)next_buffer_ptr, fixptr);
-        next_buffer_ptr = (uint8_t*)fixptr;
-    }
-    assert(((uintptr_t)next_buffer_ptr & 0b111111u) == 0);
-    uint dpram_offset = hw_data_offset(ep->hw_data_buf);
-    assert(hw_data_offset(next_buffer_ptr) <= USB_DPRAM_MAX);
+  ep->hw_data_buf = next_buffer_ptr;
+  next_buffer_ptr += size;
 
-    pico_info("Alloced %d bytes at offset 0x%x (0x%p) for ep %d %s\n",
-                size,
-                dpram_offset,
-                ep->hw_data_buf,
-                tu_edpt_number(ep->ep_addr),
-                ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
+  assert(((uintptr_t )next_buffer_ptr & 0b111111u) == 0);
+  uint dpram_offset = hw_data_offset(ep->hw_data_buf);
+  assert(hw_data_offset(next_buffer_ptr) <= USB_DPRAM_MAX);
 
-    // Fill in endpoint control register with buffer offset
-    uint32_t reg =  EP_CTRL_ENABLE_BITS
-                  | EP_CTRL_INTERRUPT_PER_BUFFER
-                  | (ep->transfer_type << EP_CTRL_BUFFER_TYPE_LSB)
-                  | dpram_offset;
+  pico_info("Alloced %d bytes at offset 0x%x (0x%p) for ep %d %s\n",
+            size,
+            dpram_offset,
+            ep->hw_data_buf,
+            tu_edpt_number(ep->ep_addr),
+            ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
 
-    *ep->endpoint_control = reg;
+  // Fill in endpoint control register with buffer offset
+  uint32_t const reg = EP_CTRL_ENABLE_BITS | (ep->transfer_type << EP_CTRL_BUFFER_TYPE_LSB) | dpram_offset;
+
+  *ep->endpoint_control = reg;
 }
 
 static void _hw_endpoint_init(struct hw_endpoint *ep, uint8_t ep_addr, uint16_t wMaxPacketSize, uint8_t transfer_type)
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index de3a83be9..f8d36e5eb 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -108,7 +108,8 @@ void _hw_endpoint_buffer_control_update32(struct hw_endpoint *ep, uint32_t and_m
     *ep->buffer_control = value;
 }
 
-static uint32_t compute_buffer_control(struct hw_endpoint *ep, uint8_t buf_id)
+// prepare buffer, return buffer control
+static uint32_t prepare_ep_buffer(struct hw_endpoint *ep, uint8_t buf_id)
 {
   uint16_t const buflen = tu_min16(ep->remaining_len, ep->wMaxPacketSize);
   ep->remaining_len -= buflen;
@@ -122,14 +123,13 @@ static uint32_t compute_buffer_control(struct hw_endpoint *ep, uint8_t buf_id)
   if ( !ep->rx )
   {
     // Copy data from user buffer to hw buffer
-    memcpy(ep->hw_data_buf, ep->user_buf, buflen);
+    memcpy(ep->hw_data_buf + buf_id*64, ep->user_buf, buflen);
     ep->user_buf += buflen;
 
     // Mark as full
     buf_ctrl |= USB_BUF_CTRL_FULL;
   }
 
-#if TUSB_OPT_HOST_ENABLED
   // Is this the last buffer? Only really matters for host mode. Will trigger
   // the trans complete irq but also stop it polling. We only really care about
   // trans complete for setup packets being sent
@@ -137,7 +137,6 @@ static uint32_t compute_buffer_control(struct hw_endpoint *ep, uint8_t buf_id)
   {
     buf_ctrl |= USB_BUF_CTRL_LAST;
   }
-#endif
 
   if (buf_id) buf_ctrl = buf_ctrl << 16;
 
@@ -150,14 +149,14 @@ static void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
   uint32_t ep_ctrl = *ep->endpoint_control;
 
   // always compute buffer 0
-  uint32_t buf_ctrl = compute_buffer_control(ep, 0);
+  uint32_t buf_ctrl = prepare_ep_buffer(ep, 0);
 
   if(ep->remaining_len)
   {
     // Use buffer 1 (double buffered) if there is still data
     // TODO: Isochronous for buffer1 bit-field is different than CBI (control bulk, interrupt)
 
-    buf_ctrl |= compute_buffer_control(ep, 1);
+    buf_ctrl |= prepare_ep_buffer(ep, 1);
 
     // Set endpoint control double buffered bit if needed
     ep_ctrl &= ~EP_CTRL_INTERRUPT_PER_BUFFER;

From 5c567129ea34ea78833cee2bf38e4e09cbdee389 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Sun, 13 Jun 2021 18:30:26 +0700
Subject: [PATCH 18/19] fix calculating xferred bytes with double buffer with
 short packet on buffer0

---
 src/portable/raspberrypi/rp2040/dcd_rp2040.c | 26 +++++++++++---------
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 22 +++++++++++------
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index 4f70d60cc..b87951421 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -67,8 +67,11 @@ static void _hw_endpoint_alloc(struct hw_endpoint *ep)
   // size must be multiple of 64
   uint16_t size = tu_div_ceil(ep->wMaxPacketSize, 64) * 64u;
 
-  // double buffered for non-ISO endpoint
-  if ( ep->transfer_type != TUSB_XFER_ISOCHRONOUS ) size *= 2u;
+  // double buffered for Control and Bulk endpoint
+  if ( ep->transfer_type == TUSB_XFER_CONTROL || ep->transfer_type == TUSB_XFER_BULK)
+  {
+    size *= 2u;
+  }
 
   ep->hw_data_buf = next_buffer_ptr;
   next_buffer_ptr += size;
@@ -445,18 +448,17 @@ void dcd_connect(uint8_t rhport)
 
 void dcd_edpt0_status_complete(uint8_t rhport, tusb_control_request_t const * request)
 {
-    pico_trace("dcd_edpt0_status_complete %d\n", rhport);
-    assert(rhport == 0);
+  (void) rhport;
 
-    if (request->bmRequestType_bit.recipient == TUSB_REQ_RCPT_DEVICE &&
-        request->bmRequestType_bit.type == TUSB_REQ_TYPE_STANDARD &&
-        request->bRequest == TUSB_REQ_SET_ADDRESS)
-    {
-        pico_trace("Set HW address %d\n", request->wValue);
-        usb_hw->dev_addr_ctrl = (uint8_t) request->wValue;
-    }
+  if ( request->bmRequestType_bit.recipient == TUSB_REQ_RCPT_DEVICE &&
+       request->bmRequestType_bit.type == TUSB_REQ_TYPE_STANDARD &&
+       request->bRequest == TUSB_REQ_SET_ADDRESS )
+  {
+    pico_trace("Set HW address %d\n", request->wValue);
+    usb_hw->dev_addr_ctrl = (uint8_t) request->wValue;
+  }
 
-    reset_ep0();
+  reset_ep0();
 }
 
 bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index f8d36e5eb..5b2a5f5a0 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -170,6 +170,7 @@ static void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
 
   *ep->endpoint_control = ep_ctrl;
 
+  TU_LOG(3, "Prepare Buffer Control:\r\n");
   print_bufctrl32(buf_ctrl);
 
   // Finally, write to buffer_control which will trigger the transfer
@@ -201,7 +202,8 @@ void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t to
   _hw_endpoint_lock_update(ep, -1);
 }
 
-static void sync_ep_buffer(struct hw_endpoint *ep, uint8_t buf_id)
+// sync endpoint buffer and return transferred bytes
+static uint16_t sync_ep_buffer(struct hw_endpoint *ep, uint8_t buf_id)
 {
   uint32_t buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
   if (buf_id)  buf_ctrl = buf_ctrl >> 16;
@@ -227,14 +229,14 @@ static void sync_ep_buffer(struct hw_endpoint *ep, uint8_t buf_id)
   }
 
   // Short packet
-  // TODO what if we prepare double buffered but receive short packet on buffer 0 !!!
-  // would the buffer status  or trans complete interrupt is triggered
   if (xferred_bytes < ep->wMaxPacketSize)
   {
-    pico_trace("Short rx transfer\n");
+    pico_trace("Short rx transfer on buffer %d with %u bytes\n", buf_id, xferred_bytes);
     // Reduce total length as this is last packet
     ep->remaining_len = 0;
   }
+
+  return xferred_bytes;
 }
 
 static void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
@@ -242,11 +244,15 @@ static void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
   // Update hw endpoint struct with info from hardware
   // after a buff status interrupt
 
-  // always sync buffer 0
-  sync_ep_buffer(ep, 0);
+  uint32_t buf_ctrl = _hw_endpoint_buffer_control_get_value32(ep);
+  TU_LOG(3, "_hw_endpoint_xfer_sync:\r\n");
+  print_bufctrl32(buf_ctrl);
 
-  // sync buffer 1 if double buffered
-  if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
+  // always sync buffer 0
+  uint16_t buf0_bytes = sync_ep_buffer(ep, 0);
+
+  // sync buffer 1 if double buffered and buffer 0 is not short packet
+  if ( ((*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS) && (buf0_bytes == ep->wMaxPacketSize) )
   {
     sync_ep_buffer(ep, 1);
   }

From 832d22d7addf9b1e4b88556c544f60bd9fa32dd6 Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Thu, 17 Jun 2021 01:55:35 +0700
Subject: [PATCH 19/19] force single buffered for device mode, out endpoint

---
 src/device/usbd.c                            |  3 +-
 src/portable/raspberrypi/rp2040/dcd_rp2040.c | 15 +++---
 src/portable/raspberrypi/rp2040/rp2040_usb.c | 52 +++++++++++++++++---
 src/portable/raspberrypi/rp2040/rp2040_usb.h |  4 +-
 4 files changed, 55 insertions(+), 19 deletions(-)

diff --git a/src/device/usbd.c b/src/device/usbd.c
index 2935defd0..587d487dc 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -1254,14 +1254,13 @@ bool usbd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t
 
   if ( dcd_edpt_xfer(rhport, ep_addr, buffer, total_bytes) )
   {
-    TU_LOG2("OK\r\n");
     return true;
   }else
   {
     // DCD error, mark endpoint as ready to allow next transfer
     _usbd_dev.ep_status[epnum][dir].busy = false;
     _usbd_dev.ep_status[epnum][dir].claimed = 0;
-    TU_LOG2("failed\r\n");
+    TU_LOG2("FAILED\r\n");
     TU_BREAKPOINT();
     return false;
   }
diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index b87951421..f78a932f1 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -145,6 +145,7 @@ static void _hw_endpoint_init(struct hw_endpoint *ep, uint8_t ep_addr, uint16_t
 
         // Now if it hasn't already been done
         //alloc a buffer and fill in endpoint control register
+        // TODO device may change configuration (dynamic), should clear and reallocate
         if(!(ep->configured))
         {
             _hw_endpoint_alloc(ep);
@@ -194,9 +195,6 @@ static void hw_handle_buff_status(void)
     {
         if (remaining_buffers & bit)
         {
-            uint __unused which = (usb_hw->buf_cpu_should_handle & bit) ? 1 : 0;
-            // Should be single buffered
-            assert(which == 0);
             // clear this in advance
             usb_hw_clear->buf_status = bit;
             // IN transfer for even i, OUT transfer for odd i
@@ -463,7 +461,7 @@ void dcd_edpt0_status_complete(uint8_t rhport, tusb_control_request_t const * re
 
 bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
 {
-    pico_info("dcd_edpt_open %d %02x\n", rhport, desc_edpt->bEndpointAddress);
+    pico_info("dcd_edpt_open %02x\n", desc_edpt->bEndpointAddress);
     assert(rhport == 0);
     hw_endpoint_init(desc_edpt->bEndpointAddress, desc_edpt->wMaxPacketSize.size, desc_edpt->bmAttributes.xfer);
     return true;
@@ -478,14 +476,14 @@ bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t t
 
 void dcd_edpt_stall (uint8_t rhport, uint8_t ep_addr)
 {
-    pico_trace("dcd_edpt_stall %d %02x\n", rhport, ep_addr);
+    pico_trace("dcd_edpt_stall %02x\n", ep_addr);
     assert(rhport == 0);
     hw_endpoint_stall(ep_addr);
 }
 
 void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
 {
-    pico_trace("dcd_edpt_clear_stall %d %02x\n", rhport, ep_addr);
+    pico_trace("dcd_edpt_clear_stall %02x\n", ep_addr);
     assert(rhport == 0);
     hw_endpoint_clear_stall(ep_addr);
 }
@@ -493,8 +491,11 @@ void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
 
 void dcd_edpt_close (uint8_t rhport, uint8_t ep_addr)
 {
+    (void) rhport;
+    (void) ep_addr;
+
     // usbd.c says: In progress transfers on this EP may be delivered after this call
-    pico_trace("dcd_edpt_close %d %02x\n", rhport, ep_addr);
+    pico_trace("dcd_edpt_close %02x\n", ep_addr);
 }
 
 void dcd_int_handler(uint8_t rhport)
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.c b/src/portable/raspberrypi/rp2040/rp2040_usb.c
index 5b2a5f5a0..dc12e6d82 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.c
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.c
@@ -148,10 +148,15 @@ static void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
 {
   uint32_t ep_ctrl = *ep->endpoint_control;
 
-  // always compute buffer 0
-  uint32_t buf_ctrl = prepare_ep_buffer(ep, 0);
+  // always compute and start with buffer 0
+  uint32_t buf_ctrl = prepare_ep_buffer(ep, 0) | USB_BUF_CTRL_SEL;
 
-  if(ep->remaining_len)
+  // For now: skip double buffered for Device mode, OUT endpoint since
+  // host could send < 64 bytes and cause short packet on buffer0
+  // NOTE this could happen to Host mode IN endpoint
+  bool const force_single = !(usb_hw->main_ctrl & USB_MAIN_CTRL_HOST_NDEVICE_BITS) && !tu_edpt_dir(ep->ep_addr);
+
+  if(ep->remaining_len && !force_single)
   {
     // Use buffer 1 (double buffered) if there is still data
     // TODO: Isochronous for buffer1 bit-field is different than CBI (control bulk, interrupt)
@@ -181,8 +186,7 @@ static void _hw_endpoint_start_next_buffer(struct hw_endpoint *ep)
 void hw_endpoint_xfer_start(struct hw_endpoint *ep, uint8_t *buffer, uint16_t total_len)
 {
   _hw_endpoint_lock_update(ep, 1);
-  pico_trace("Start transfer of total len %d on ep %d %s\n", total_len, tu_edpt_number(ep->ep_addr),
-             ep_dir_string[tu_edpt_dir(ep->ep_addr)]);
+
   if ( ep->active )
   {
     // TODO: Is this acceptable for interrupt packets?
@@ -251,10 +255,42 @@ static void _hw_endpoint_xfer_sync (struct hw_endpoint *ep)
   // always sync buffer 0
   uint16_t buf0_bytes = sync_ep_buffer(ep, 0);
 
-  // sync buffer 1 if double buffered and buffer 0 is not short packet
-  if ( ((*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS) && (buf0_bytes == ep->wMaxPacketSize) )
+  // sync buffer 1 if double buffered
+  if ( (*ep->endpoint_control) & EP_CTRL_DOUBLE_BUFFERED_BITS )
   {
-    sync_ep_buffer(ep, 1);
+    if (buf0_bytes == ep->wMaxPacketSize)
+    {
+      // sync buffer 1 if not short packet
+      sync_ep_buffer(ep, 1);
+    }else
+    {
+      // short packet on buffer 0
+      // TODO couldn't figure out how to handle this case which happen with net_lwip_webserver example
+      // At this time (currently trigger per 2 buffer), the buffer1 is probably filled with data from
+      // the next transfer (not current one). For now we disable double buffered for device OUT
+      // NOTE this could happen to Host IN
+#if 0
+      uint8_t const ep_num = tu_edpt_number(ep->ep_addr);
+      uint8_t const dir =  (uint8_t) tu_edpt_dir(ep->ep_addr);
+      uint8_t const ep_id = 2*ep_num + (dir ? 0 : 1);
+
+      // abort queued transfer on buffer 1
+      usb_hw->abort |= TU_BIT(ep_id);
+
+      while ( !(usb_hw->abort_done & TU_BIT(ep_id)) ) {}
+
+      uint32_t ep_ctrl = *ep->endpoint_control;
+      ep_ctrl &= ~(EP_CTRL_DOUBLE_BUFFERED_BITS | EP_CTRL_INTERRUPT_PER_DOUBLE_BUFFER);
+      ep_ctrl |= EP_CTRL_INTERRUPT_PER_BUFFER;
+
+      _hw_endpoint_buffer_control_set_value32(ep, 0);
+
+      usb_hw->abort &= ~TU_BIT(ep_id);
+
+      TU_LOG(3, "----SHORT PACKET buffer0 on EP %02X:\r\n", ep->ep_addr);
+      print_bufctrl32(buf_ctrl);
+#endif
+    }
   }
 }
 
diff --git a/src/portable/raspberrypi/rp2040/rp2040_usb.h b/src/portable/raspberrypi/rp2040/rp2040_usb.h
index 4c787f496..514152cd9 100644
--- a/src/portable/raspberrypi/rp2040/rp2040_usb.h
+++ b/src/portable/raspberrypi/rp2040/rp2040_usb.h
@@ -120,8 +120,8 @@ static inline void print_bufctrl16(uint32_t u16)
       .u16 = u16
   };
 
-  TU_LOG(3, "len = %u, available = %u, stall = %u, reset = %u, toggle = %u, last = %u, full = %u\r\n",
-         bufctrl.xfer_len, bufctrl.available, bufctrl.stall, bufctrl.reset_bufsel, bufctrl.data_toggle, bufctrl.last_buf, bufctrl.full);
+  TU_LOG(3, "len = %u, available = %u, full = %u, last = %u, stall = %u, reset = %u, toggle = %u\r\n",
+         bufctrl.xfer_len, bufctrl.available, bufctrl.full, bufctrl.last_buf, bufctrl.stall, bufctrl.reset_bufsel, bufctrl.data_toggle);
 }
 
 static inline void print_bufctrl32(uint32_t u32)