ixgb: Fix early TSO completion
This fix was already merged in commit 96f9c2e277768099479fbed7c3b69c294b1fadef
but reverted in commit 989316ddfeafd0e8fb51a4d811383769ad62637a. After
stresstesting we found that the fix does not add new regressions and
works around a TX hang spotted by several users.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index e628126..70ac9d4 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -1287,6 +1287,7 @@
struct ixgb_buffer *buffer_info;
int len = skb->len;
unsigned int offset = 0, size, count = 0, i;
+ unsigned int mss = skb_shinfo(skb)->gso_size;
unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
unsigned int f;
@@ -1298,6 +1299,11 @@
while(len) {
buffer_info = &tx_ring->buffer_info[i];
size = min(len, IXGB_MAX_DATA_PER_TXD);
+ /* Workaround for premature desc write-backs
+ * in TSO mode. Append 4-byte sentinel desc */
+ if (unlikely(mss && !nr_frags && size == len && size > 8))
+ size -= 4;
+
buffer_info->length = size;
WARN_ON(buffer_info->dma != 0);
buffer_info->dma =
@@ -1324,6 +1330,13 @@
while(len) {
buffer_info = &tx_ring->buffer_info[i];
size = min(len, IXGB_MAX_DATA_PER_TXD);
+
+ /* Workaround for premature desc write-backs
+ * in TSO mode. Append 4-byte sentinel desc */
+ if (unlikely(mss && !nr_frags && size == len
+ && size > 8))
+ size -= 4;
+
buffer_info->length = size;
buffer_info->dma =
pci_map_page(adapter->pdev,
@@ -1401,8 +1414,9 @@
/* Tx Descriptors needed, worst case */
#define TXD_USE_COUNT(S) (((S) >> IXGB_MAX_TXD_PWR) + \
(((S) & (IXGB_MAX_DATA_PER_TXD - 1)) ? 1 : 0))
-#define DESC_NEEDED TXD_USE_COUNT(IXGB_MAX_DATA_PER_TXD) + \
- MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1
+#define DESC_NEEDED TXD_USE_COUNT(IXGB_MAX_DATA_PER_TXD) /* skb->date */ + \
+ MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1 /* for context */ \
+ + 1 /* one more needed for sentinel TSO workaround */
static int
ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)