[Intel-gfx] [PATCH 01/16] drm/i915: vlv: fix gunit HW state corruption during S4 suspend

[Sagar Arun Kamble]

Thanks Imre.

Reviewed-by: Sagar Kamble <sagar.a.kamble at intel.com>
On Mon, 2014-09-15 at 20:42 +0300, Imre Deak wrote:
> The point of doing these in thaw_early is to work around an ordering
> issue wrt. to the hda driver, see the comment in i915_resume_early(). I
> don't see a problem of having them in thaw_early; if you meant that they
> lack the corresponding cleanup calls in freeze_late, it's just because
> they don't have any.
> 
> On Mon, 2014-09-15 at 22:56 +0530, Sagar Arun Kamble wrote:
> > From DPM documentation, thaw_early should undo actions by freeze_late.
> > Can we move following snippet from thaw_early to thaw to comply with
> > this?
> > 
> > 	intel_uncore_early_sanitize(dev, true);
> >         intel_uncore_sanitize(dev);
> >         intel_power_domains_init_hw(dev_priv);
> > 
> > On Wed, 2014-09-10 at 18:16 +0300, Imre Deak wrote:
> > > During S4 freeze we don't call intel_suspend_complete(), which would
> > > save the gunit HW state, but during S4 thaw/restore events we call
> > > intel_resume_prepare() which restores it, thus ending up in a corrupted
> > > HW state.
> > > 
> > > Fix this by calling intel_suspend_complete() from the corresponding
> > > freeze_late event handler.
> > > 
> > > The issue was introduced in
> > > commit 016970beb05da6285c2f3ed2bee1c676cb75972e
> > > Author: Sagar Kamble <sagar.a.kamble at intel.com>
> > > Date:   Wed Aug 13 23:07:06 2014 +0530
> > > 
> > > CC: Sagar Kamble <sagar.a.kamble at intel.com>
> > > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/i915_drv.c | 10 ++++++++++
> > >  1 file changed, 10 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > > index b8bd008..2365875 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.c
> > > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > > @@ -987,6 +987,15 @@ static int i915_pm_freeze(struct device *dev)
> > >  	return i915_drm_freeze(drm_dev);
> > >  }
> > >  
> > > +static int i915_pm_freeze_late(struct device *dev)
> > > +{
> > > +	struct pci_dev *pdev = to_pci_dev(dev);
> > > +	struct drm_device *drm_dev = pci_get_drvdata(pdev);
> > > +	struct drm_i915_private *dev_priv = drm_dev->dev_private;
> > > +
> > > +	return intel_suspend_complete(dev_priv);
> > > +}
> > > +
> > >  static int i915_pm_thaw_early(struct device *dev)
> > >  {
> > >  	struct pci_dev *pdev = to_pci_dev(dev);
> > > @@ -1571,6 +1580,7 @@ static const struct dev_pm_ops i915_pm_ops = {
> > >  	.resume_early = i915_pm_resume_early,
> > >  	.resume = i915_pm_resume,
> > >  	.freeze = i915_pm_freeze,
> > > +	.freeze_late = i915_pm_freeze_late,
> > >  	.thaw_early = i915_pm_thaw_early,
> > >  	.thaw = i915_pm_thaw,
> > >  	.poweroff = i915_pm_poweroff,
> > 
> > 
> 
>