Quoting Ville Syrjala (2020-10-01 16:16:35) > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Implement the pci .shutdown() hook in order to quiesce the > hardware prior to reboot. The main purpose here is to turn > all displays off. Some displays/other drivers tend to get > confused if the state after reboot isn't exactly as they > expected. > > One specific example was the Dell UP2414Q in MST mode. > It would require me to pull the power cord after a reboot > or else it would just not come back to life. Sadly I don't > have that at hand anymore so not sure if it's still > misbehaving without the graceful shutdown, or if we > managed to fix something else since I last tested it. > > For good measure we do a gem suspend as well, so that > we match the suspend flow more closely. Also stopping > all DMA and whatnot is probably a good idea for kexec. > I would expect that some kind of GT reset happens on > normal reboot so probably not totally necessary there. Note that we should do a reset just in case kexec [whatever comes next] fails or forgets, depending on your level of paranoia. So device shutdown is called from the reboot/halt pathways, bypassing the usual suspend/remove. > v2: Use the pci .shutdown() hook instead of a reboot notifier (Lukas) > Do the gem suspend for kexec (Chris) We could do with a little bit more force than i915_gem_suspend, but baby steps. I was trying to think how we could squeeze a kexec test into CI. I don't know kexec well enough to devise a robust igt. Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
