This is a note to let you know that I've just added the patch titled net: stmmac: fix watchdog timeout during suspend/resume stress test to the 4.19-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-watchdog-timeout-during-suspend-resume-stress-test.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c511819d138de38e1637eedb645c207e09680d0f Mon Sep 17 00:00:00 2001 From: Joakim Zhang <qiangqing.zhang@xxxxxxx> Date: Thu, 25 Feb 2021 17:01:11 +0800 Subject: net: stmmac: fix watchdog timeout during suspend/resume stress test From: Joakim Zhang <qiangqing.zhang@xxxxxxx> commit c511819d138de38e1637eedb645c207e09680d0f upstream. stmmac_xmit() call stmmac_tx_timer_arm() at the end to modify tx timer to do the transmission cleanup work. Imagine such a situation, stmmac enters suspend immediately after tx timer modified, it's expire callback stmmac_tx_clean() would not be invoked. This could affect BQL, since netdev_tx_sent_queue() has been called, but netdev_tx_completed_queue() have not been involved, as a result, dql_avail(&dev_queue->dql) finally always return a negative value. __dev_queue_xmit->__dev_xmit_skb->qdisc_run->__qdisc_run->qdisc_restart->dequeue_skb: if ((q->flags & TCQ_F_ONETXQUEUE) && netif_xmit_frozen_or_stopped(txq)) // __QUEUE_STATE_STACK_XOFF is set Net core will stop transmitting any more. Finillay, net watchdong would timeout. To fix this issue, we should call netdev_tx_reset_queue() in stmmac_resume(). Fixes: 54139cf3bb33 ("net: stmmac: adding multiple buffers for rx") Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -4566,6 +4566,8 @@ static void stmmac_reset_queues_param(st tx_q->cur_tx = 0; tx_q->dirty_tx = 0; tx_q->mss = 0; + + netdev_tx_reset_queue(netdev_get_tx_queue(priv->dev, queue)); } } Patches currently in stable-queue which might be from qiangqing.zhang@xxxxxxx are queue-4.19/net-stmmac-stop-each-tx-channel-independently.patch queue-4.19/can-flexcan-enable-rx-fifo-after-frz-halt-valid.patch queue-4.19/net-stmmac-fix-watchdog-timeout-during-suspend-resume-stress-test.patch queue-4.19/can-flexcan-assert-frz-bit-in-flexcan_chip_freeze.patch