[Intel-gfx] [PATCH 11/12] drm/i915/bdw: Ensure a context is loaded before RC6

[Chris Wilson]

On Wed, Mar 19, 2014 at 06:31:18PM -0700, Ben Widawsky wrote:
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index ee32759..4de8800 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2436,6 +2436,7 @@ void i915_gem_reset(struct drm_device *dev)
>  static void
>  i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
>  {
> +	struct drm_i915_private *dev_priv = ring->dev->dev_private;
>  	uint32_t seqno;
>  
>  	if (list_empty(&ring->request_list))
> @@ -2459,6 +2460,15 @@ i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
>  		if (!i915_seqno_passed(seqno, obj->last_read_seqno))
>  			break;
>  
> +		/* Wa: can't find the w/a name.
> +		 * This doesn't actually implement the w/a, but it a workaround
> +		 * for the workaround. It defers using rc6 until we know valid
> +		 * state exists.
> +		 */
> +		if (IS_BROADWELL(ring->dev) && intel_enable_rc6(ring->dev) &&
> +		    !dev_priv->rps.enabled && ring->id == RCS)
> +			intel_enable_gt_powersave(ring->dev);
> +

This is a big eyesore. I think we will both be happy if you move this to
intel_mark_idle(). You can then check for ring[RCS]->last_context being
set.

>  		i915_gem_object_move_to_inactive(obj);
>  	}

-- 
Chris Wilson, Intel Open Source Technology Centre