FAILED: patch "[PATCH] net: fix spurious TX timeout after dev_activate()" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] net: fix spurious TX timeout after dev_activate()" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 82aeed2400786bd3f79d88cb8b8f42e6127e5923
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090352-stinking-autism-dd92@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 82aeed2400786bd3f79d88cb8b8f42e6127e5923 Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao@debian.org>
Date: Tue, 25 Aug 2026 03:50:10 -0700
Subject: [PATCH] net: fix spurious TX timeout after dev_activate()

While debugging another issue today, I found out that my TX queue is
reported as stopped for 4294907392 ms (49.7 days), on a machine that
had been up for four minutes.

    bnxt_en 0002:01:00.0 eth0: NETDEV WATCHDOG: CPU: 28: transmit queue 23 timed out 4294907392 ms

4294907392 is not an elapsed time. It is the value of jiffies at that
moment: INITIAL_JIFFIES is 4294667296, which leaves jiffies 59 seconds
short of wrapping.

dev_activate() runs transition_one_qdisc() over every TX queue, which
resets trans_start to 0, and then stamps only queue 0 through
netif_trans_update().

Stamp jiffies instead. A queue stopped across dev_activate() now gets a
full watchdog_timeo of grace, and is still reported if it is stopped
that long.

Fixes: 9b36627acecd ("net: remove dev->trans_start")
Cc: stable@vger.kernel.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20260825-trans_start-v2-1-286b4d6d70cb@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index ef2b4bf51564..4539dc2c6d38 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1278,7 +1278,7 @@ static void transition_one_qdisc(struct net_device *dev,
 
 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
 	if (need_watchdog_p) {
-		WRITE_ONCE(dev_queue->trans_start, 0);
+		WRITE_ONCE(dev_queue->trans_start, jiffies);
 		*need_watchdog_p = 1;
 	}
 }

[PATCH 5.10.y 1/2] net: annotate accesses to queue->trans_start

[Sasha Levin]

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 5337824f4dc4bb26f38fbbba4ffb425a92803f15 ]

In following patches, dev_watchdog() will no longer stop all queues.
It will read queue->trans_start locklessly.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Backport to 5.15: retain only the transition_one_qdisc() annotation
needed by 82aeed2400786bd3f79d88cb8b8f42e6127e5923 ("net: fix spurious TX
timeout after dev_activate()"). This preserves the zero timestamp while
providing the WRITE_ONCE() context that the target changes to jiffies.

Drop the virtio hunk because this tree has no virtnet_tx_timeout(). Drop
the other annotations and helper conversion because they are unrelated
to the target; no new functions are introduced. The 5.15 watchdog still
holds the transmit locks, so the broader lockless-access preparation is
not required for this dependency.

[ sashal: Reduced backport -- upstream 5337824f4dc4b touches 14 file(s), this
  backport carries 1. Not backported here:
  drivers/net/ethernet/apm/xgene/xgene_enet_main.c
  drivers/net/ethernet/atheros/ag71xx.c
  drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
  drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
  drivers/net/ethernet/ibm/ibmvnic.c
  drivers/net/ethernet/intel/igb/igb_main.c
  drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
  ... and 5 more
  This note is generated from the file lists only; see the resolution record
  for the reasoning. ]

Stable-dep-of: 82aeed240078 ("net: fix spurious TX timeout after dev_activate()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/sched/sch_generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 243a1d6b349c7..d55b010285739 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1149,7 +1149,7 @@ static void transition_one_qdisc(struct net_device *dev,
 
 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
 	if (need_watchdog_p) {
-		dev_queue->trans_start = 0;
+		WRITE_ONCE(dev_queue->trans_start, 0);
 		*need_watchdog_p = 1;
 	}
 }
-- 
2.53.0

[PATCH 5.10.y 2/2] net: fix spurious TX timeout after dev_activate()

[Sasha Levin]

From: Breno Leitao <leitao@debian.org>

[ Upstream commit 82aeed2400786bd3f79d88cb8b8f42e6127e5923 ]

While debugging another issue today, I found out that my TX queue is
reported as stopped for 4294907392 ms (49.7 days), on a machine that
had been up for four minutes.

    bnxt_en 0002:01:00.0 eth0: NETDEV WATCHDOG: CPU: 28: transmit queue 23 timed out 4294907392 ms

4294907392 is not an elapsed time. It is the value of jiffies at that
moment: INITIAL_JIFFIES is 4294667296, which leaves jiffies 59 seconds
short of wrapping.

dev_activate() runs transition_one_qdisc() over every TX queue, which
resets trans_start to 0, and then stamps only queue 0 through
netif_trans_update().

Stamp jiffies instead. A queue stopped across dev_activate() now gets a
full watchdog_timeo of grace, and is still reported if it is stopped
that long.

Fixes: 9b36627acecd ("net: remove dev->trans_start")
Cc: stable@vger.kernel.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20260825-trans_start-v2-1-286b4d6d70cb@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/sched/sch_generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index d55b010285739..b5fc998b53f43 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1149,7 +1149,7 @@ static void transition_one_qdisc(struct net_device *dev,
 
 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
 	if (need_watchdog_p) {
-		WRITE_ONCE(dev_queue->trans_start, 0);
+		WRITE_ONCE(dev_queue->trans_start, jiffies);
 		*need_watchdog_p = 1;
 	}
 }
-- 
2.53.0