From 3c96819a2c9399440a8c579b360bbd65d971c349 Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon>
Date: Fri, 26 Mar 2010 16:54:15 +0000
Subject: [PATCH] Make LWIP_NETIF_TX_SINGLE_PBUF work for TCP, too

---
 CHANGELOG          | 3 +++
 src/core/init.c    | 4 ++--
 src/core/tcp_out.c | 9 +++++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 420b8c05..ee35db38 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -169,6 +169,9 @@ HISTORY
 
   ++ Bugfixes:
 
+  2010-03-26: Simon Goldschmidt
+  * tcp_out.c: Make LWIP_NETIF_TX_SINGLE_PBUF work for TCP, too
+
   2010-03-26: Simon Goldschmidt
   * various files: Fixed compiling with different options disabled (TCP/UDP),
     triggered by bug #29345; don't allocate acceptmbox if LWIP_TCP is disabled
diff --git a/src/core/init.c b/src/core/init.c
index b22b3a83..3ddd49a8 100644
--- a/src/core/init.c
+++ b/src/core/init.c
@@ -181,8 +181,8 @@
 #if LWIP_TCPIP_CORE_LOCKING_INPUT && !LWIP_TCPIP_CORE_LOCKING
   #error "When using LWIP_TCPIP_CORE_LOCKING_INPUT, LWIP_TCPIP_CORE_LOCKING must be enabled, too"
 #endif
-#if LWIP_TCP && LWIP_NETIF_TX_SINGLE_PBUF && (TCP_OVERSIZE < TCP_MSS)
-  #error "LWIP_NETIF_TX_SINGLE_PBUF needs TCP_OVERSIZE == TCP_MSS to create single-pbuf TCP packets"
+#if LWIP_TCP && LWIP_NETIF_TX_SINGLE_PBUF && !TCP_OVERSIZE
+  #error "LWIP_NETIF_TX_SINGLE_PBUF needs TCP_OVERSIZE enabled to create single-pbuf TCP packets"
 #endif
 
 
diff --git a/src/core/tcp_out.c b/src/core/tcp_out.c
index e8e7db7b..a2bce4d2 100644
--- a/src/core/tcp_out.c
+++ b/src/core/tcp_out.c
@@ -221,6 +221,14 @@ tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
   struct pbuf *p;
   u16_t alloc = length;
 
+#if LWIP_NETIF_TX_SINGLE_PBUF
+  LWIP_UNUSED_ARG(max_length);
+  LWIP_UNUSED_ARG(pcb);
+  LWIP_UNUSED_ARG(apiflags);
+  LWIP_UNUSED_ARG(first_seg);
+  /* always create MSS-sized pbufs */
+  alloc = TCP_MSS;
+#else /* LWIP_NETIF_TX_SINGLE_PBUF */
   if (length < max_length) {
     /* Should we allocate an oversized pbuf, or just the minimum
      * length required? If tcp_write is going to be called again
@@ -241,6 +249,7 @@ tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
       alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
     }
   }
+#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
   p = pbuf_alloc(layer, alloc, PBUF_RAM);
   if (p == NULL) {
     return NULL;