[Intel-gfx] [PATCH] drm/i915: leave rc6 enabled at suspend time v4

[Jesse Barnes]

On Wed, 11 Jun 2014 15:21:16 -0700
Jesse Barnes <jbarnes at virtuousgeek.org> wrote:

> On Tue, 10 Jun 2014 17:26:45 +0200
> Daniel Vetter <daniel at ffwll.ch> wrote:
> 
> > On Tue, Jun 10, 2014 at 05:41:49PM +0300, Imre Deak wrote:
> > > On Tue, 2014-06-10 at 15:57 +0200, Daniel Vetter wrote:
> > > > On Tue, Jun 10, 2014 at 04:42:50PM +0300, Imre Deak wrote:
> > > > > On Wed, 2014-06-04 at 13:45 -0700, Jesse Barnes wrote:
> > > > > > This allows the system to enter the lowest power mode during system freeze.
> > > > > > 
> > > > > > v2: delete force wake timer at suspend (Imre)
> > > > > > v3: add GT work suspend function (Imre)
> > > > > > v4: use uncore forcewake reset (Daniel)
> > > > > > 
> > > > > > Signed-off-by: Kristen Carlson Accardi <kristen at linux.intel.com>
> > > > > > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> > > > > > ---
> > > > > >  drivers/gpu/drm/i915/i915_drv.c     |  4 ++--
> > > > > >  drivers/gpu/drm/i915/i915_drv.h     |  1 +
> > > > > >  drivers/gpu/drm/i915/intel_drv.h    |  1 +
> > > > > >  drivers/gpu/drm/i915/intel_pm.c     | 20 ++++++++++++++++++++
> > > > > >  drivers/gpu/drm/i915/intel_uncore.c |  2 +-
> > > > > >  5 files changed, 25 insertions(+), 3 deletions(-)
> > > > > > 
> > > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > > > > > index 66c6ffb..7148eac 100644
> > > > > > --- a/drivers/gpu/drm/i915/i915_drv.c
> > > > > > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > > > > > @@ -521,7 +521,7 @@ static int i915_drm_freeze(struct drm_device *dev)
> > > > > >  		drm_irq_uninstall(dev);
> > > > > >  		dev_priv->enable_hotplug_processing = false;
> > > > > >  
> > > > > > -		intel_disable_gt_powersave(dev);
> > > > > > +		intel_suspend_gt_powersave(dev);
> > > > > 
> > > > > I realized now that we actually do need to enable RC6 explicitly. If we
> > > > > get here right after runtime resume, the deferred RC6 enabling might be
> > > > > still pending and so RC6 might not be enabled.
> 
> Seems like we could just flush the enable if it was outstanding?

Oh and I see we already have the flush in v4... do you think we might
not actually arm the deferred enable work before we get here?  I think
the runtime_resume and suspend calls should be serialized, but if not
we'd need some locking I guess...

Jesse