On Monday, April 24, 2017 10:42:42 PM Lukas Wunner wrote: > On Mon, Apr 24, 2017 at 10:02:30PM +0200, Lukas Wunner wrote: > > On Mon, Apr 24, 2017 at 05:27:42PM +0300, Imre Deak wrote: > > > Some drivers - like i915 - may not support the system suspend direct > > > complete optimization due to differences in their runtime and system > > > suspend sequence. Add a flag that when set resumes the device before > > > calling the driver's system suspend handlers which effectively disables > > > the optimization. > > > > FWIW, there are at least two alternative solutions to this problem which > > do not require changes to the PCI core: > > > > (1) Add a ->prepare hook to i915_pm_ops which calls pm_runtime_get_sync() > > and a ->complete hook which calls pm_runtime_put(). > > Thinking a bit more about this, it's even simpler: The PM core acquires > a runtime PM ref in device_prepare() and releases it in device_complete(), > so it's sufficient to just call pm_runtime_resume() in a ->prepare hook > that's newly added to i915. No ->complete hook necessary. Tentative > patch below, based on drm-intel-fixes, would replace both of your patches. Calling it in ->prepare() means that everybody is now waiting for you to resume. Not quite optimal IMO. Thanks, Rafael
