On Fri, 23 Aug 2013 13:49:57 -0300 Paulo Zanoni <przanoni@xxxxxxxxx> wrote: > 2013/8/22 Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>: > > On Wed, 21 Aug 2013 15:29:17 +0000 > > "Lin, Mengdong" <mengdong.lin@xxxxxxxxx> wrote: > > > >> Hi Ben, > >> > >> How will Gfx driver support runtime PM on Haswell? Will the Gfx driver trigger "Adapter Power State" notification to BIOS when GPU switch state between D0 and D3? > >> > >> We need to support RTD3 for HD-A legacy audio on Haswell Ultrabook. And this depends on Gfx driver to implement two BIOS notifications. > >> > >> Here is the background of this dependency: > >> The target of HD-Audio RTD3 is that BIOS can power off the on-board 3rd party audio codec to save power in S0. This would help to save ~60mW. > >> Please note that audio driver cannot power off the codec, because the codec power is controlled by some GPIO which is board specific. > >> > >> The BIOS will power off the audio codec when three requirements are met: > >> > >> (1) System is running on battery > >> > >> (2) HD-Audio controller is in D3. Means no active audio application is using the audio devices. > >> > >> (3) All displays are off. This means system is in "User-Absent Mode", and a long latency for devices to resume back to D0 is allowed, such as ~300ms to power on the audio codec. > >> > >> For the 3rd requirement, BIOS needs Gfx driver to tell whether the system is in user-absent mode. It needs Gfx driver to triger two SCI SW notifications: Display Power State Notification and Adapter Power State Notification. > >> 'Display Power State Notification' was implemented by Jani. But we were told that 'Adapter Power State' notification needs Gfx driver to support runtime PM at first. > >> > >> So would you please share some information about runtime PM support in Gfx driver? > > > > Paulo was going to test this on top of his PC8+ patchset. AFAFIK the > > only thing we need to do is put the device into D3 when we enter the > > PC8+ mode, and the BIOS will do the right thing (when we use the > > OpRegion stuff Jani did anyway). > > > > Paulo, are you still out celebrating the PC8 bits or have you had a > > chance to try this yet? > > From Mengdong's email, it seems Jani's patch series implements exactly > what was requested, except for the fact that our patch says "D1" > instead of "D3" to the BIOS. Is there something else we need besides > this? I don't think so... well except for testing. :) If you have something that seems to work it's probably worthwhile to get Kristen to try it out on her instrumented setup. -- Jesse Barnes, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
