Patch "net: stmmac: fix completely hung TX when using TSO" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

net: stmmac: fix completely hung TX when using TSO

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-stmmac-fix-completely-hung-tx-when-using-tso.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Niklas Cassel <[email protected]>
Date: Tue, 6 Jun 2017 09:25:00 +0200
Subject: net: stmmac: fix completely hung TX when using TSO

From: Niklas Cassel <[email protected]>

[ Upstream commit 426849e6611f2092553f8d53372ae310818a6292 ]

stmmac_tso_allocator can fail to set the Last Descriptor bit on a descriptor that actually was the last descriptor.

This happens when the buffer of the last descriptor ends up having a size of exactly TSO_MAX_BUFF_SIZE.

When the IP eventually reaches the next last descriptor, which actually has the bit set, the DMA will hang.

When the DMA hangs, we get a tx timeout, however, since stmmac does not do a complete reset of the IP in stmmac_tx_timeout, we end up in a state with completely hung TX.

---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -1953,7 +1953,7 @@ static void stmmac_tso_allocator(struct
 
 		priv->hw->desc->prepare_tso_tx_desc(desc, 0, buff_size,
 			0, 1,
-			(last_segment) && (buff_size < TSO_MAX_BUFF_SIZE),
+			(last_segment) && (tmp_len <= TSO_MAX_BUFF_SIZE),
 			0, 0);
 
 		tmp_len -= TSO_MAX_BUFF_SIZE;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/net-stmmac-fix-completely-hung-tx-when-using-tso.patch