[Intel-gfx] [PATCH 12/15] drm/i915: Interrupt routing for GuC submission

[Chris Wilson]

On Mon, Jun 15, 2015 at 07:36:30PM +0100, Dave Gordon wrote:
> +static void direct_interrupts_to_guc(struct drm_i915_private *dev_priv)
> +{
> +	struct intel_engine_cs *ring;
> +	int i, irqs;
> +
> +	/* tell all command streamers to forward interrupts and vblank to GuC */
> +	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_ALWAYS);
> +	irqs |= _MASKED_BIT_ENABLE(GFX_INTERRUPT_STEERING);
> +	for_each_ring(ring, dev_priv, i)
> +		I915_WRITE(RING_MODE_GEN7(ring), irqs);
> +
> +	/* tell DE to send (all) flip_done to GuC */
> +	irqs = DERRMR_PIPEA_PRI_FLIP_DONE | DERRMR_PIPEA_SPR_FLIP_DONE |
> +	       DERRMR_PIPEB_PRI_FLIP_DONE | DERRMR_PIPEB_SPR_FLIP_DONE |
> +	       DERRMR_PIPEC_PRI_FLIP_DONE | DERRMR_PIPEC_SPR_FLIP_DONE;
> +	/* Unmasked bits will cause GuC response message to be sent */
> +	I915_WRITE(DE_GUCRMR, ~irqs);

That's scary since userspace depends on a few more DERRMR events
(wait-for-scanline). Where will they end up?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre