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_h4_ehcill_dma: fix race condition and use volatile

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This commit is contained in:
Matthias Ringwald 2015-12-04 12:15:13 +01:00
parent 3723a70091
commit 9734c7fa37
1 changed files with 20 additions and 15 deletions
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35
src/hci_transport_h4_ehcill_dma.c
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@ -54,9 +54,9 @@
#include "debug.h"
#include "hci.h"
#include "hci_transport.h"
#include <btstack/run_loop.h>
#include "run_loop.h"
#include <btstack/hal_uart_dma.h>
#include "hal_uart_dma.h"
// #include <libopencm3/stm32/gpio.h>
// #define GPIO_DEBUG_0 GPIO1
@ -125,9 +125,9 @@ static uint16_t ehcill_defer_rx_size = 0;
static uint8_t ehcill_command_to_send;
// H4: packet reader state machine
static H4_STATE h4_state;
static int read_pos;
static int bytes_to_read;
static volatile H4_STATE h4_state;
static int read_pos;
static int bytes_to_read;
// bigger than largest packet
static uint8_t hci_packet_prefixed[HCI_INCOMING_PRE_BUFFER_SIZE + HCI_PACKET_BUFFER_SIZE];
@ -136,8 +136,8 @@ static uint8_t * hci_packet = &hci_packet_prefixed[HCI_INCOMING_PRE_BUFFER_SIZE]
static void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
// H4: tx state
static TX_STATE tx_state;
static int tx_send_packet_sent;
static volatile TX_STATE tx_state; // updated from block_sent callback
static volatile int tx_send_packet_sent; // updated from block_sent callback
static uint8_t * tx_data;
static uint16_t tx_len;
static uint8_t tx_packet_type;
@ -225,11 +225,10 @@ static int h4_close(void *transport_config){
return 0;
}
// potentially called from ISR context
static void h4_block_received(void){
// gpio_set(GPIOB, GPIO_DEBUG_0);
read_pos += bytes_to_read;
read_pos += bytes_to_read;
// act
switch (h4_state) {
@ -300,11 +299,10 @@ static void h4_block_received(void){
static int h4_can_send_packet_now(uint8_t packet_type){
return tx_state == TX_IDLE;
}
static void ehcill_sleep_ack_timer_handler(timer_source_t * timer){
tx_state = TX_W4_EHCILL_SENT;
// gpio_clear(GPIOB, GPIO_DEBUG_1);
hal_uart_dma_send_block(&ehcill_command_to_send, 1);
}
@ -316,6 +314,7 @@ static void ehcill_sleep_ack_timer_setup(void){
embedded_trigger();
}
// potentially called from ISR context
static void h4_block_sent(void){
switch (tx_state){
case TX_W4_HEADER_SENT:
@ -324,22 +323,22 @@ static void h4_block_sent(void){
hal_uart_dma_send_block(tx_data, tx_len);
break;
case TX_W4_PACKET_SENT:
// non-ehcill packet sent, confirm
tx_send_packet_sent = 1;
// send pending ehcill command if neccessary
switch (ehcill_command_to_send){
case EHCILL_GO_TO_SLEEP_ACK:
ehcill_sleep_ack_timer_setup();
tx_send_packet_sent = 1;
break;
case EHCILL_WAKE_UP_IND:
tx_state = TX_W4_EHCILL_SENT;
// gpio_clear(GPIOB, GPIO_DEBUG_1);
hal_uart_dma_send_block(&ehcill_command_to_send, 1);
tx_send_packet_sent = 1;
break;
default:
// trigger run loop
tx_state = TX_DONE;
tx_send_packet_sent = 1;
embedded_trigger();
break;
}
@ -369,6 +368,12 @@ static int h4_process(struct data_source *ds) {
// notify about packet sent
if (tx_send_packet_sent){
// race condition: if tx_state was set after our check, can_send_now will fail, causing a hang
// workaround: assert that tx_state is TX_IDLE if it was just set to done by ISR
if (tx_state == TX_DONE){
tx_state = TX_IDLE;
}
tx_send_packet_sent = 0;
uint8_t event[] = { DAEMON_EVENT_HCI_PACKET_SENT, 0 };
packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));