[Mesa-dev] [PATCH 2/2] intel: Fall back to X-tiling when larger than estimated aperture size.

[Chad Versace]

On 04/10/2013 02:08 PM, Kenneth Graunke wrote:
> If a region is larger than the estimated aperture size, we map/unmap it
> by copying with the BLT engine.  Which means we can't use Y-tiling.
>
> Fixes Piglit max-texture-size and tex3d-maxsize, which regressed in my
> recent change to use Y-tiling by default on Gen6+.  This was due to a
> botched merge conflict resolution.
>
> v2: Return a mask of valid tilings from intel_miptree_select_tiling.
>      This allows us to avoid the X-tiling fallback if Y-tiling is actually
>      mandatory.
>
> Cc: Paul Berry <stereotype441 at gmail.com>
> Cc: Chad Versace <chad.versace at linux.intel.com>
> Cc: Eric Anholt <eric at anholt.net>
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>   src/mesa/drivers/dri/intel/intel_mipmap_tree.c | 28 ++++++++++++++++++++++++--
>   1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> index 8fcdb46..d7908c1 100644
> --- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> +++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> @@ -352,7 +352,11 @@ intel_miptree_choose_tiling(struct intel_context *intel,
>         return I915_TILING_NONE;
>      }
>
> -   return intel->gen >= 6 ? I915_TILING_Y : I915_TILING_X;
> +   /* Pre-gen6 doesn't have BLORP to handle Y-tiling, so use X-tiling. */
> +   if (intel->gen < 6)
> +      return I915_TILING_X;
> +
> +   return I915_TILING_Y | I915_TILING_X;
>   }
>
>   struct intel_mipmap_tree *
> @@ -432,13 +436,33 @@ intel_miptree_create(struct intel_context *intel,
>      uint32_t tiling = intel_miptree_choose_tiling(intel, format, width0,
>                                                    num_samples, force_y_tiling,
>                                                    mt);
> +   bool y_or_x = tiling == (I915_TILING_Y | I915_TILING_X);
> +
>      mt->etc_format = etc_format;
>      mt->region = intel_region_alloc(intel->intelScreen,
> -				   tiling,
> +				   y_or_x ? I915_TILING_Y : tiling,
>   				   mt->cpp,
>   				   total_width,
>   				   total_height,
>   				   expect_accelerated_upload);
> +
> +   /* If the region is too large to fit in the aperture, we need to use the
> +    * BLT engine to support it.  The BLT paths can't currently handle Y-tiling,
> +    * so we need to fall back to X.
> +    */
> +   if (y_or_x && mt->region->bo->size >= intel->max_gtt_map_object_size) {
> +      perf_debug("%dx%d miptree larger than aperture; falling back to X-tiled\n",
> +                 mt->total_width, mt->total_height);
> +      intel_region_release(&mt->region);
> +
> +      mt->region = intel_region_alloc(intel->intelScreen,
> +                                      I915_TILING_X,
> +                                      mt->cpp,
> +                                      total_width,
> +                                      total_height,
> +                                      expect_accelerated_upload);
> +   }
> +
>      mt->offset = 0;
>
>      if (!mt->region) {
>

Looks good to me.
Reviewed-by: Chad Versace <chad.versace at linux.intel.com>