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

Ville Syrjälä
2014-04-09T16:53:45Z

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@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@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@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