[Intel-gfx] [PATCH] drm/i915/bdw: Use timeout mode for RC6 on bdw

[Daniel Vetter]

On Mon, Jun 02, 2014 at 09:51:27PM +0000, O'Rourke, Tom wrote:
> >From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel Vetter
> >Sent: Monday, June 02, 2014 1:26 AM
> >To: O'Rourke, Tom
> >Cc: intel-gfx at lists.freedesktop.org; Ben Widawsky; Kristen Carlson Accardi
> >Subject: Re: [Intel-gfx] [PATCH] drm/i915/bdw: Use timeout mode for RC6 on
> >bdw
> >
> >On Fri, May 30, 2014 at 11:30:18PM +0000, O'Rourke, Tom wrote:
> >> >On Wed, Apr 30, 2014 at 02:14:02PM -0700, Kristen Carlson Accardi wrote:
> >> >> On Thu, 01 May 2014 00:03:15 +0300
> >> >> Imre Deak <imre.deak at intel.com> wrote:
> >> >>
> >> >> > On Wed, 2014-04-30 at 13:41 -0700, Ben Widawsky wrote:
> >> >> > > On Wed, Apr 30, 2014 at 01:34:36PM -0700, Kristen Carlson Accardi
> >wrote:
> >> >> > > > On Tue, 29 Apr 2014 22:31:49 -0700 Ben Widawsky
> >> >> > > > <ben at bwidawsk.net> wrote:
> >> >> > > >
> >> >> > > > > On Wed, Apr 09, 2014 at 11:44:06AM -0700, Tom O'Rourke wrote:
> >> >> > > > > > Higher RC6 residency is observed using timeout mode
> >> >> > > > > > instead of EI mode.  This applies to Broadwell only.
> >> >> > > > > > The difference is particularly noticeable with video
> >> >> > > > > > playback.
> >> >> > > > > >
> >> >> > > > > > Issue: VIZ-3778
> >> >> > > > > > Change-Id: I62bb12e21caf19651034826b45cde7f73a80938d
> >> >> > > > > > Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
> >> >> > > > >
> >> >> > > > > I've merged this one to my bdw-rc6 branch, and therefore my
> >> >> > > > > broadwell branch. Hopefully Kristen will see some improvement.
> >> >> > > >
> >> >> > > > Unfortunately, I built your bdw-rc6 branch along with the
> >> >> > > > revert I need to get my panel to work, and I get zero rc6 residency.
> >> >> > > > Do I have to explicitly enable it?
> >> >> > >
> >> >> > > I'm not actually sure. You can try it and let me know. I
> >> >> > > haven't had any time to verify the rebase. We can check my hack.
> >> >> >
> >> >> > Note that in -nightly you also have to update
> >> >> > sanitize_rc6_option() along with intel_enable_gt_powersave() and
> >> >> > intel_disable_gt_powersave() since atm these keep RC6 disabled on BDW.
> >> >> >
> >> >> > --Imre
> >> >> >
> >> >>
> >> >>
> >> >> Yes, I reverted fb5ed3b201fe5670c9ffeec3b5f6ff044d543c9e and was
> >> >> able to see some rc6 residency.  With the idle workload, residency
> >> >> appears to be similar to before, so no regression.
> >> >
> >> >Thanks. I'll squash this in where appropriate.
> >> >
> >> >--
> >> >Ben Widawsky, Intel Open Source Technology Center
> >>
> >> [TOR:] Can we get this patch merged now that RC6 is working on drm-intel-
> >nightly?
> >
> >Needs some review from bdw people. Also some relative residency
> >improvement date should be added to the commit message (yes, we're allowed
> >to do that now officially).
> >-Daniel
> >--
> 
> [TOR:] Hello bdw people, please review this patch.
> 
> Is relative performance data now required in the commit message?  A week
> ago this would have been prohibited.

You might need to double-check with your own manager, but we're now again
allowed to officially add it to the commit message. It was kinda always
required, just had to be washed down more.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch