On Wed, 12 Aug 2020, Lyude Paul wrote: > On Wed, 2020-08-12 at 16:10 +0200, Daniel Vetter wrote: > > On Wed, Aug 12, 2020 at 12:16 AM Zwane Mwaikambo <zwanem@xxxxxxxxx> wrote: > > > On Tue, 11 Aug 2020, Daniel Vetter wrote: > > > > > > > On Mon, Aug 10, 2020 at 10:11:50AM -0700, Zwane Mwaikambo wrote: > > > > > Hi Folks, > > > > > I know this thread eventually dropped off due to not identifying > > > > > the underlying issue. It's still occuring on 5.8 and in my case it > > > > > happened because the udev device nodes for the DP aux devices were not > > > > > cleaned up whereas the kernel had no association with them. I can > > > > > reproduce the bug just by creating a device node for a non-existent > > > > > minor > > > > > device and calling open(). > > > > > > > > Hm I don't have that thread anymore, but generally these bugs are solved > > > > by not registering the device before it's ready for use. We do have > > > > drm_connector->late_register for that stuff. Just a guess since I'm not > > > > seeing full details here. > > > > > > In this particular case, the physical device disappeared before the nodes > > > were cleaned up. It involves putting a computer to sleep with a monitor > > > plugged in and then waking it up with the monitor unplugged. > > > > We also have early_unregister for the reverse, but yes this sounds > > more tricky ... Adding Lyude who's been working on way too much > > lifetime fun around dp recently. > > -Daniel > > > Hi-I think just checking whether the auxdev is NULL or not is a reasonable > fix, although I am curious as to how exactly the aux dev's parent is getting > destroyed before it's child, which I would have thought would be the only way > you could hit this? Hi, If this is acceptable, would you consider an updated patch against 5.8? Thanks, Zwane _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
