From: Paul Berry Date: Tue, 12 Nov 2013 18:55:18 +0000 (-0800) Subject: i965: Fix vertical alignment for multisampled buffers. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b4c3b833ec8ec6787658ea90365ff565cd8846c7;p=mesa.git i965: Fix vertical alignment for multisampled buffers. From the Sandy Bridge PRM, Vol 1 Part 1 7.18.3.4 (Alignment Unit Size): j [vertical alignment] = 4 for any render target surface is multisampled (4x) From the Ivy Bridge PRM, Vol 4 Part 1 2.12.2.1 (SURFACE_STATE for most messages), under the "Surface Vertical Alignment" heading: This field is intended to be set to VALIGN_4 if the surface was rendered as a depth buffer, for a multisampled (4x) render target, or for a multisampled (8x) render target, since these surfaces support only alignment of 4. Back in 2012 when we added multisampling support to the i965 driver, we forgot to update the logic for computing the vertical alignment, so we were often using a vertical alignment of 2 for multisampled buffers, leading to subtle rendering errors. Note that the specs also require a vertical alignment of 4 for all Y-tiled render target surfaces; I plan to address that in a separate patch. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=53077 Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Kenneth Graunke Reviewed-by: Eric Anholt --- diff --git a/src/mesa/drivers/dri/i965/brw_tex_layout.c b/src/mesa/drivers/dri/i965/brw_tex_layout.c index d912862e50b..d05dbeb0201 100644 --- a/src/mesa/drivers/dri/i965/brw_tex_layout.c +++ b/src/mesa/drivers/dri/i965/brw_tex_layout.c @@ -86,7 +86,7 @@ intel_horizontal_texture_alignment_unit(struct brw_context *brw, static unsigned int intel_vertical_texture_alignment_unit(struct brw_context *brw, - gl_format format) + gl_format format, bool multisampled) { /** * From the "Alignment Unit Size" section of various specs, namely: @@ -110,8 +110,6 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw, * * On SNB+, non-special cases can be overridden by setting the SURFACE_STATE * "Surface Vertical Alignment" field to VALIGN_2 or VALIGN_4. - * - * We currently don't support multisampling. */ if (_mesa_is_format_compressed(format)) return 4; @@ -119,6 +117,9 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw, if (format == MESA_FORMAT_S8) return brw->gen >= 7 ? 8 : 4; + if (multisampled) + return 4; + GLenum base_format = _mesa_get_format_base_format(format); if (brw->gen >= 6 && @@ -276,8 +277,10 @@ brw_miptree_layout_texture_3d(struct brw_context *brw, void brw_miptree_layout(struct brw_context *brw, struct intel_mipmap_tree *mt) { + bool multisampled = mt->num_samples > 1; mt->align_w = intel_horizontal_texture_alignment_unit(brw, mt->format); - mt->align_h = intel_vertical_texture_alignment_unit(brw, mt->format); + mt->align_h = + intel_vertical_texture_alignment_unit(brw, mt->format, multisampled); switch (mt->target) { case GL_TEXTURE_CUBE_MAP: