[Intel-gfx] [PATCH 52/71] drm/i915/chv: Make CHV irq handler loop until all interrupts are consumed

[Ville Syrjälä]

On Wed, Apr 09, 2014 at 06:05:01PM +0200, Daniel Vetter wrote:
> On Wed, Apr 09, 2014 at 01:28:50PM +0300, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Really, this is what the hw guys tell us to do? I mean we've never had a
> gmch based platform which didn't need this, but I've thought with all the
> gen8 irq restructuring they'd finally fix this ...

This came from Rafael's observations. I was hoping re-enabling the
master interrupt bit would have retriggered the CPU interrupt if any
IIR bits were still high, but I guess that's not the case :(

> 
> /me cries
> 
> Cheers, Daniel
> 
> > ---
> >  drivers/gpu/drm/i915/i915_irq.c | 29 ++++++++++++++---------------
> >  1 file changed, 14 insertions(+), 15 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> > index 9702fde..fc9b7e6 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -1775,30 +1775,29 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
> >  	u32 master_ctl, iir;
> >  	irqreturn_t ret = IRQ_NONE;
> >  
> > -	master_ctl = I915_READ(GEN8_MASTER_IRQ) & ~DE_MASTER_IRQ_CONTROL;
> > -	iir = I915_READ(VLV_IIR);
> > +	for (;;) {
> > +		master_ctl = I915_READ(GEN8_MASTER_IRQ) & ~GEN8_MASTER_IRQ_CONTROL;
> > +		iir = I915_READ(VLV_IIR);
> >  
> > -	if (master_ctl == 0 && iir == 0)
> > -		return IRQ_NONE;
> > +		if (master_ctl == 0 && iir == 0)
> > +			break;
> >  
> > -	I915_WRITE(GEN8_MASTER_IRQ, 0);
> > +		I915_WRITE(GEN8_MASTER_IRQ, 0);
> >  
> > -	gen8_gt_irq_handler(dev, dev_priv, master_ctl);
> > +		gen8_gt_irq_handler(dev, dev_priv, master_ctl);
> >  
> > -	valleyview_pipestat_irq_handler(dev, iir);
> > +		valleyview_pipestat_irq_handler(dev, iir);
> >  
> > -	/* Consume port.  Then clear IIR or we'll miss events */
> > -	if (iir & I915_DISPLAY_PORT_INTERRUPT) {
> > +		/* Consume port.  Then clear IIR or we'll miss events */
> >  		i9xx_hpd_irq_handler(dev, iir);
> > -		ret = IRQ_HANDLED;
> > -	}
> >  
> > -	I915_WRITE(VLV_IIR, iir);
> > +		I915_WRITE(VLV_IIR, iir);
> >  
> > -	I915_WRITE(GEN8_MASTER_IRQ, DE_MASTER_IRQ_CONTROL);
> > -	POSTING_READ(GEN8_MASTER_IRQ);
> > +		I915_WRITE(GEN8_MASTER_IRQ, DE_MASTER_IRQ_CONTROL);
> > +		POSTING_READ(GEN8_MASTER_IRQ);
> >  
> > -	ret = IRQ_HANDLED;
> > +		ret = IRQ_HANDLED;
> > +	}
> >  
> >  	return ret;
> >  }
> > -- 
> > 1.8.3.2
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Ville Syrjälä
Intel OTC