Re: [PATCH v3] virtio_net: avoid using netif_tx_disable() for serializing tx routine

[David Miller]

From: Ake Koomsin <ake@xxxxxxxxxx>
Date: Wed, 17 Oct 2018 19:44:12 +0900

> Commit 713a98d90c5e ("virtio-net: serialize tx routine during reset")
> introduces netif_tx_disable() after netif_device_detach() in order to
> avoid use-after-free of tx queues. However, there are two issues.
> 
> 1) Its operation is redundant with netif_device_detach() in case the
>    interface is running.
> 2) In case of the interface is not running before suspending and
>    resuming, the tx does not get resumed by netif_device_attach().
>    This results in losing network connectivity.
> 
> It is better to use netif_tx_lock_bh()/netif_tx_unlock_bh() instead for
> serializing tx routine during reset. This also preserves the symmetry
> of netif_device_detach() and netif_device_attach().
> 
> Fixes commit 713a98d90c5e ("virtio-net: serialize tx routine during reset")
> Signed-off-by: Ake Koomsin <ake@xxxxxxxxxx>

Applied and queued up for -stable.