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

stmmac: reset last TSO segment size after device open

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: stmmac-reset-last-tso-segment-size-after-device-open.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Dec 14 11:45:40 CET 2017

From: Lars Persson lars.persson@axis.com Date: Fri, 1 Dec 2017 11:12:44 +0100 Subject: stmmac: reset last TSO segment size after device open

From: Lars Persson lars.persson@axis.com

[ Upstream commit 45ab4b13e46325d00f4acdb365d406e941a15f81 ]

The mss variable tracks the last max segment size sent to the TSO engine. We do not update the hardware as long as we receive skb:s with the same value in gso_size.

During a network device down/up cycle (mapped to stmmac_release() and stmmac_open() callbacks) we issue a reset to the hardware and it forgets the setting for mss. However we did not zero out our mss variable so the next transmission of a gso packet happens with an undefined hardware setting.

This triggers a hang in the TSO engine and eventuelly the netdev watchdog will bark.

Fixes: f748be531d70 ("stmmac: support new GMAC4") Signed-off-by: Lars Persson larper@axis.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 1 + 1 file changed, 1 insertion(+)

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2564,6 +2564,7 @@ static int stmmac_open(struct net_device

priv->dma_buf_sz = STMMAC_ALIGN(buf_sz); priv->rx_copybreak = STMMAC_RX_COPYBREAK; + priv->mss = 0;

ret = alloc_dma_desc_resources(priv); if (ret < 0) {

Patches currently in stable-queue which might be from lars.persson@axis.com are

queue-4.14/stmmac-reset-last-tso-segment-size-after-device-open.patch