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 4.9-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:
stmmac-reset-last-tso-segment-size-after-device-open.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 <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Dec 14 11:45:58 CET 2017
From: Lars Persson <lars.persson@xxxxxxxx>
Date: Fri, 1 Dec 2017 11:12:44 +0100
Subject: stmmac: reset last TSO segment size after device open
From: Lars Persson <lars.persson@xxxxxxxx>
[ 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@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -1795,6 +1795,7 @@ 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@xxxxxxxx are
queue-4.9/stmmac-reset-last-tso-segment-size-after-device-open.patch