On 23.09.2020 22:15, David Miller wrote: > From: Heiner Kallweit <hkallwe...@gmail.com> > Date: Wed, 23 Sep 2020 21:58:59 +0200 > >> On 23.09.2020 20:35, Saeed Mahameed wrote: >>> Why would a driver detach the device on ndo_stop() ? >>> seems like this is the bug you need to be chasing .. >>> which driver is doing this ? >>> >> Some drivers set the device to PCI D3hot at the end of ndo_stop() >> to save power (using e.g. Runtime PM). Marking the device as detached >> makes clear to to the net core that the device isn't accessible any >> longer. > > That being the case, the problem is that IFF_UP+!present is not a > valid netdev state. > If this combination is invalid, then netif_device_detach() should clear IFF_UP? At a first glance this should be sufficient to avoid the issue I was dealing with.
> Is it simply the issue that, upon resume, IFF_UP is marked true before > the device is brought out from D3hot state and thus marked as present > again? > I can't really comment on that. The issue I was dealing with at the time I submitted this change was about an async linkwatch event (caused by powering down the PHY in ndo_stop) trying to access the device when it was powered down already.
