[PATCH 09/18] drm/i915: make PM interrupt writes non-destructive

[damien.lespiau at intel.com (Damien Lespiau)]

On Sat, Apr 27, 2013 at 05:59:20PM -0700, Ben Widawsky wrote:
> @@ -2720,12 +2720,12 @@ static void gen6_enable_rps(struct drm_device *dev)
>  	gen6_set_rps(dev_priv->dev, (gt_perf_status & 0xff00) >> 8);
>  
>  	/* requires MSI enabled */
> -	I915_WRITE(GEN6_PMIER, GEN6_PM_DEFERRED_EVENTS);
> +	I915_WRITE(GEN6_PMIER, I915_READ(GEN6_PMIER) | GEN6_PM_RPS_EVENTS);
>  	spin_lock_irq(&dev_priv->rps.lock);
>  	WARN_ON(dev_priv->rps.pm_iir != 0);
> -	I915_WRITE(GEN6_PMIMR, 0);
> +	I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);

You're not unmasking the RPS interrupts in PMIMR here now. I'm missing
how they are enabled now.

>  	spin_unlock_irq(&dev_priv->rps.lock);
> -	/* enable all PM interrupts */
> +	/* unmask all PM interrupts */
>  	I915_WRITE(GEN6_PMINTRMSK, 0);
>
>  	rc6vids = 0;