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 ed04033..c04fb94 100644 (file)
--- 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;
                }