[PATCH net] ionic: tame the watchdog timer on reconfig

[Shannon Nelson]

Even with moving netif_tx_disable() to an earlier point when
taking down the queues for a reconfiguration, we still end
up with the occasional netdev watchdog Tx Timeout complaint.
The old method of using netif_trans_update() works fine for
queue 0, but has no effect on the remaining queues.  Using
netif_device_detach() allows us to signal to the watchdog to
ignore us for the moment.

Fixes: beead698b173 ("ionic: Add the basic NDO callbacks for netdev support")
Signed-off-by: Shannon Nelson <snel...@pensando.io>
---
 drivers/net/ethernet/pensando/ionic/ionic_lif.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c 
b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index 8f29ef133743..aaa00edd9d5b 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -1694,15 +1694,15 @@ static void ionic_stop_queues(struct ionic_lif *lif)
        if (!test_and_clear_bit(IONIC_LIF_F_UP, lif->state))
                return;
 
-       ionic_txrx_disable(lif);
        netif_tx_disable(lif->netdev);
+       ionic_txrx_disable(lif);
 }
 
 int ionic_stop(struct net_device *netdev)
 {
        struct ionic_lif *lif = netdev_priv(netdev);
 
-       if (!netif_device_present(netdev))
+       if (test_bit(IONIC_LIF_F_FW_RESET, lif->state))
                return 0;
 
        ionic_stop_queues(lif);
@@ -1985,18 +1985,19 @@ int ionic_reset_queues(struct ionic_lif *lif)
        bool running;
        int err = 0;
 
-       /* Put off the next watchdog timeout */
-       netif_trans_update(lif->netdev);
-
        err = ionic_wait_for_bit(lif, IONIC_LIF_F_QUEUE_RESET);
        if (err)
                return err;
 
        running = netif_running(lif->netdev);
-       if (running)
+       if (running) {
+               netif_device_detach(lif->netdev);
                err = ionic_stop(lif->netdev);
-       if (!err && running)
+       }
+       if (!err && running) {
                ionic_open(lif->netdev);
+               netif_device_attach(lif->netdev);
+       }
 
        clear_bit(IONIC_LIF_F_QUEUE_RESET, lif->state);
 
-- 
2.17.1