From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Sat, 6 Sep 2014 17:51:44 +0000 (+0000)
Subject: ar71xx: fix off-by-one error in packet descriptor splitting (patch from #13072)
X-Git-Url: https://git.archive.openwrt.org/?p=openwrt.git;a=commitdiff_plain;h=ce722f2a950a4ec9c2262076b00425b1d4082c04

ar71xx: fix off-by-one error in packet descriptor splitting (patch from #13072)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42428 3c298f89-4303-0410-b956-a3cf2f4a3e73
---

diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
index ed04033341..c04fb94b94 100644
--- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
@@ -704,7 +704,12 @@ static int ag71xx_fill_dma_desc(struct ag71xx_ring *ring, u32 addr, int len)
 
 		if (cur_len > split) {
 			cur_len = split;
-			if (len < split + 4)
+
+			/*
+			 * TX will hang if DMA transfers <= 4 bytes,
+			 * make sure next segment is more than 4 bytes long.
+			 */
+			if (len <= split + 4)
 				cur_len -= 4;
 		}