Re: [PATCH] Revert "net: linkwatch: add check for netdevice being present to linkwatch_do_dev"

[David Miller]

From: David Miller <da...@davemloft.net>
Date: Wed, 23 Sep 2020 17:21:25 -0700 (PDT)

> If an async code path tests 'present', gets true, and then the RTNL
> holding synchronous code path puts the device into D3hot immediately
> afterwards, the async code path will still continue and access the
> chips registers and fault.

Wait, is the sequence:

        ->ndo_stop()
                mark device not present and put into D3hot
                triggers linkwatch event
          ...
                         ->ndo_get_stats64()

???

Then yeah we might have to clear IFF_UP at the beginning of taking
a netdev down.