[Intel-gfx] [PATCH 07/10] drm/i915: Support for pread/pwrite from/to non shmem backed objects

[Chris Wilson]

On Mon, Jan 11, 2016 at 05:15:54PM +0000, Tvrtko Ursulin wrote:
> > Is that not what was written? I take it my telepathy isn't working
> > again.
> 
> Sorry not a new loop, new case in a old loop. This is the hunk I think
> is not helping readability:
> 
> @@ -869,11 +967,29 @@ i915_gem_gtt_pwrite_fast(struct drm_i915_private *i915,
>  		/* If we get a fault while copying data, then (presumably) our
>  		 * source page isn't available.  Return the error and we'll
>  		 * retry in the slow path.
> +		 * If the object is non-shmem backed, we retry again with the
> +		 * path that handles page fault.
>  		 */
> -		if (fast_user_write(i915->gtt.mappable, page_base,
> -				    page_offset, user_data, page_length)) {
> -			ret = -EFAULT;
> -			goto out_flush;
> +		if (faulted || fast_user_write(i915->gtt.mappable,
> +						page_base, page_offset,
> +						user_data, page_length)) {
> +			if (!obj->base.filp) {

This is just wrong, we neither need the faulted nor the difference in
behaviour based on storage.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre