From 3e55f3e88b40471706d5cd45c4df4010f8675c75 Mon Sep 17 00:00:00 2001 From: Chad Versace Date: Mon, 18 Jul 2011 00:38:00 -0700 Subject: 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 Date: Mon Jul 18 00:37:45 2011 -0700 Signed-off-by: Chad Versace Reviewed-by: Ian Romanick Acked-by: Kenneth Graunke --- src/intel_dri.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/src/intel_dri.c b/src/intel_dri.c index 5ea7c2ca..90f9b8fe 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; } -- cgit v1.2.3