Re: [net PATCH] hv_netvsc: Fix unwanted wakeup in netvsc_attach()

From: David Miller
Date: Sun Feb 23 2020 - 19:33:07 EST

From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Date: Fri, 21 Feb 2020 08:32:18 -0800

> When netvsc_attach() is called by operations like changing MTU, etc.,
> an extra wakeup may happen while netvsc_attach() calling
> rndis_filter_device_add() which sends rndis messages when queue is
> stopped in netvsc_detach(). The completion message will wake up queue 0.
> We can reproduce the issue by changing MTU etc., then the wake_queue
> counter from "ethtool -S" will increase beyond stop_queue counter:
> stop_queue: 0
> wake_queue: 1
> The issue causes queue wake up, and counter increment, no other ill
> effects in current code. So we didn't see any network problem for now.
> To fix this, initialize tx_disable to true, and set it to false when
> the NIC is ready to be attached or registered.
> Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>

Applied, thank you.