On Thu, Aug 3, 2017 at 1:17 AM, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: > On Wed, Aug 2, 2017 at 10:50 PM, Alex Deucher <alexdeucher@xxxxxxxxx> wrote: >> On Wed, Aug 2, 2017 at 7:56 AM, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: >>> The only thing modern drivers are supposed to do in lastclose is >>> restore the fb emulation state. Which is entirely optional, and >>> there's really no reason to do that. So restrict it to legacy drivers >>> (where the driver cleanup essentially happens in lastclose). >> >> vga_switcheroo_process_delayed_switch() gets called in lastclose. >> Won't that need to get moved elsewhere for this to work? > > Hm right, I forgot the lazy way to do runtime pm by keeping the device > alive as long as anyone has an open fd for it ... This shouldn't be a > problem, since you need to unregister from vgaswitcheroo anyway on > unload. Maybe that blows up, I'll check the code and augment the patch > as needed. So I think there's 3 cases: - Trying to unload the module. You can't do that while anyone has the fd still open, so lastclose is guaranteeed to run. - Forcefully unbinding the driver through sysfs. Not any better, since the can_switch stuff checks for the open count, and so will delay the delayed switch no matter what. - Actual hotremoval: a) not implemented since none of the drivers taking part in vgaswitcheroo correctly unplug the drm device and b) you can't hotremove a chip from a laptop. So I think I'm not breaking this anymore than it probably already is :-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
