xf86-video-intel: src/intel_dri.c

[Chad Versace]

 src/intel_dri.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

New commits:
commit 3e55f3e88b40471706d5cd45c4df4010f8675c75
Author: Chad Versace <chad at chad-versace.us>
Date:   Mon Jul 18 00:38:00 2011 -0700

    dri: Do not tile stencil buffer
    
    Until now, the stencil buffer was allocated as a Y tiled buffer, because
    in several locations the PRM states that it is. However, it is actually
    W tiled. From the PRM, 2011 Sandy Bridge, Volume 1, Part 2, Section
    4.5.2.1 W-Major Format:
        W-Major Tile Format is used for separate stencil.
    
    The GTT is incapable of W fencing, so we allocate the stencil buffer with
    I915_TILING_NONE and decode the tile's layout in software.
    
    This commit mutually depends on the mesa commit:
        intel: Fix stencil buffer to be W tiled
        Author: Chad Versace <chad at chad-versace.us>
        Date:   Mon Jul 18 00:37:45 2011 -0700
    
    Signed-off-by: Chad Versace <chad at chad-versace.us>
    Reviewed-by: Ian Romanick <ian.romanick at intel.com>
    Acked-by: Kenneth Graunke <kenneth at whitecape.org>

diff --git a/src/intel_dri.c b/src/intel_dri.c
index 5ea7c2c..90f9b8f 100644
--- a/src/intel_dri.c
+++ b/src/intel_dri.c
@@ -336,7 +336,6 @@ I830DRI2CreateBuffer(DrawablePtr drawable, unsigned int attachment,
 			switch (attachment) {
 			case DRI2BufferDepth:
 			case DRI2BufferDepthStencil:
-			case DRI2BufferStencil:
 			case DRI2BufferHiz:
 				if (SUPPORTS_YTILING(intel)) {
 					hint |= INTEL_CREATE_PIXMAP_TILING_Y;
@@ -351,6 +350,14 @@ I830DRI2CreateBuffer(DrawablePtr drawable, unsigned int attachment,
 			case DRI2BufferFrontRight:
 				hint |= INTEL_CREATE_PIXMAP_TILING_X;
 				break;
+			case DRI2BufferStencil:
+				/*
+				 * The stencil buffer is W tiled. However, we
+				 * request from the kernel a non-tiled buffer
+				 * because the GTT is incapable of W fencing.
+				 */
+				hint |= INTEL_CREATE_PIXMAP_TILING_NONE;
+				break;
 			default:
 				free(privates);
 				free(buffer);
@@ -368,11 +375,12 @@ I830DRI2CreateBuffer(DrawablePtr drawable, unsigned int attachment,
 		 * To accomplish this, we resort to the nasty hack of doubling
 		 * the drm region's cpp and halving its height.
 		 *
-		 * If we neglect to double the pitch, then
-		 * drm_intel_gem_bo_map_gtt() maps the memory incorrectly.
+		 * If we neglect to double the pitch, then render corruption
+		 * occurs.
 		 */
 		if (attachment == DRI2BufferStencil) {
-			pixmap_height /= 2;
+			pixmap_width = ALIGN(pixmap_width, 64);
+			pixmap_height = ALIGN((pixmap_height + 1) / 2, 64);
 			pixmap_cpp *= 2;
 		}