On Wed, 2016-04-27 at 23:49 +0300, Ville Syrjälä wrote: > On Wed, Apr 27, 2016 at 01:17:15PM -0700, Todd Brandt wrote: > > On Wed, 2016-04-27 at 22:31 +0300, Ville Syrjälä wrote: > > > On Wed, Apr 27, 2016 at 11:46:22AM -0700, Todd Brandt wrote: > > > > I'd like to propose that we push the i915 suspend_late/resume_early code > > > > into suspend_noirq/resume_noirq in order to reduce the total suspend time > > > > by ~15ms. According to the comments, when i915_pm_suspend_late was first > > > > added to the kernel back in April 2014, it was done so to ensure that it > > > > was called after the snd_hda_intel driver had finished its suspend. > > > > > > > > The comments in i915_drv.c are here: > > > > > > > > /* > > > > * We have a suspedn ordering issue with the snd-hda driver also > > > > * requiring our device to be power up. Due to the lack of a > > > > * parent/child relationship we currently solve this with an late > > > > * suspend hook. > > > > * > > > > * FIXME: This should be solved with a special hdmi sink device or > > > > * similar so that power domains can be employed. > > > > */ > > > > > > > > I believe we could achieve the same ordering by simply pushing it to > > > > suspend/resume_noirq. Thus we can effectively eliminate the suspend_late > > > > and resume_early phases altogether in most simple systems. Does anyone see > > > > a problem with this? > > > > > > > > analyzesuspend outputs for freeze/suspend/hibernate (WITHOUT PATCH): > > > > https://01org.github.io/suspendresume/i915/freeze-160422-155931-ivybridge-dev-late/ > > > > https://01org.github.io/suspendresume/i915/suspend-160422-155735-ivybridge-dev-late/ > > > > https://01org.github.io/suspendresume/i915/hibernate-160422-163915-ivybridge-dev-late/ > > > > > > > > analyzesuspend outputs for freeze/suspend/hibernate (WITH PATCH): > > > > https://01org.github.io/suspendresume/i915/freeze-160422-162811-ivybridge-dev-noirq/ > > > > https://01org.github.io/suspendresume/i915/suspend-160422-162700-ivybridge-dev-noirq/ > > > > https://01org.github.io/suspendresume/i915/hibernate-160422-162952-ivybridge-dev-noirq/ > > > > > > Hmm. Looking at those makes me confused. Why isn't the pci bus > > > .resume_noirq hook (pci_pm_resume_noirq()) waking up our pci device? > > > Instead our wakeup gets delayed until .resume_early for some reason. > > > > Which timeline are you referring to? The "late" ones are the unaltered > > versions. > > Referring to the current code, ie. the "late" timeline. > Well it does wakeup with noirq in the suspend mode (S3) version: https://01org.github.io/suspendresume/i915/suspend-160422-155735-ivybridge-dev-late/ It's in freeze (S2) that it gets delayed to resume_early, which I assumed was normal (I'll try it on other systems to compare): https://01org.github.io/suspendresume/i915/freeze-160422-155931-ivybridge-dev-late/ _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
