• Joakim Zhang's avatar
    net: stmmac: fix watchdog timeout during suspend/resume stress test · c511819d
    Joakim Zhang authored
    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: 54139cf3 ("net: stmmac: adding multiple buffers for rx")
    Signed-off-by: default avatarJoakim Zhang <qiangqing.zhang@nxp.com>
    Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    c511819d
stmmac_main.c 147 KB