lkml.org 
[lkml]   [2021]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.4 254/355] ibmvnic: dont stop queue in xmit
    Date
    From: Sukadev Bhattiprolu <sukadev@linux.ibm.com>

    [ Upstream commit 8878e46fcfd46b19964bd90e13b25dd94cbfc9be ]

    If adapter's resetting bit is on, discard the packet but don't stop the
    transmit queue - instead leave that to the reset code. With this change,
    it is possible that we may get several calls to ibmvnic_xmit() that simply
    discard packets and return.

    But if we stop the queue here, we might end up doing so just after
    __ibmvnic_open() started the queues (during a hard/soft reset) and before
    the ->resetting bit was cleared. If that happens, there will be no one to
    restart queue and transmissions will be blocked indefinitely.

    This can cause a TIMEOUT reset and with auto priority failover enabled,
    an unnecessary FAILOVER reset to less favored backing device and then a
    FAILOVER back to the most favored backing device. If we hit the window
    repeatedly, we can get stuck in a loop of TIMEOUT, FAILOVER, FAILOVER
    resets leaving the adapter unusable for extended periods of time.

    Fixes: 7f5b030830fe ("ibmvnic: Free skb's in cases of failure in transmit")
    Reported-by: Abdul Haleem <abdhalee@in.ibm.com>
    Reported-by: Vaishnavi Bhat <vaish123@in.ibm.com>
    Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
    Reviewed-by: Dany Madden <drt@linux.ibm.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/net/ethernet/ibm/ibmvnic.c | 2 --
    1 file changed, 2 deletions(-)

    diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
    index cfe7229593ead..059eaa13e2c6d 100644
    --- a/drivers/net/ethernet/ibm/ibmvnic.c
    +++ b/drivers/net/ethernet/ibm/ibmvnic.c
    @@ -1462,8 +1462,6 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
    netdev_tx_t ret = NETDEV_TX_OK;

    if (test_bit(0, &adapter->resetting)) {
    - if (!netif_subqueue_stopped(netdev, skb))
    - netif_stop_subqueue(netdev, queue_num);
    dev_kfree_skb_any(skb);

    tx_send_failed++;
    --
    2.33.0


    \
     
     \ /
      Last update: 2021-11-15 19:13    [W:2.910 / U:0.120 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site