[Intel-gfx] [PATCH] drm/i915: synchronize_irq() before turning off disp2d power well on VLV/CHV

[Ville Syrjälä]

On Mon, Feb 22, 2016 at 02:37:25PM +0200, Imre Deak wrote:
> On pe, 2016-02-19 at 18:41 +0200, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > After we've told the irq code we don't want to handle display irqs
> > anymore, we must make sure any display irq handling already
> > kicked off has finished before we actually turn off the power well.
> > 
> > I wouldn't expect PIPESTAT based interrupts to occur anymore since
> > vblanks/page flips/gmbus/etc should all be quiescent at this point.
> > But at least hotplug interrupts could still occur. Hotplug
> > interrupts may also kick off the workqueue based hotplug processing,
> > but that code should take the required power domain references
> > itself, so there shouldn't be any need to synchronize with the
> > hotplug processing from the power well code.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Reviewed-by: Imre Deak <imre.deak at intel.com>

Pushed to dinq. Thanks for the review.

> 
> > ---
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index a2e367cf99a2..59e9222223c9 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -941,6 +941,9 @@ static void vlv_display_power_well_deinit(struct
> > drm_i915_private *dev_priv)
> >  	valleyview_disable_display_irqs(dev_priv);
> >  	spin_unlock_irq(&dev_priv->irq_lock);
> >  
> > +	/* make sure we're done processing display irqs */
> > +	synchronize_irq(dev_priv->dev->irq);
> > +
> >  	vlv_power_sequencer_reset(dev_priv);
> >  }
> >  

-- 
Ville Syrjälä
Intel OTC