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>

0 files changed, 0 insertions, 0 deletions