<div dir="ltr">On 9 July 2013 18:12, Anuj Phogat <<a href="mailto:anuj.phogat@gmail.com" target="_blank">anuj.phogat@gmail.com</a>> wrote: <div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> For HSW GT3 clear rectangle must be aligned to two times the number of pixels in the table shown in Ivy Bridge PRM, Vol2 Part1 11.7. It should be safe to do this for all gen7 systems unless we see any performance regressions. I observed no piglit, gles3conform regressions with this patch. </blockquote><div> </div><div>I realize it was my idea to do this for all Gen7 systems, but on further reflection, it's so easy to restrict this workaround to just HSW GT3 that I think we should go ahead and do that. Along the lines of Chris Forbes' suggestion, the code would look something like: if (brw->is_haswell && brw->gt == 3) { /* rationale ... */ x0 = ROUND_DOWN_TO(x0, 2 * x_align); y0 = ROUND_DOWN_TO(y0, 2 * y_align); x1 = ALIGN(x1, 2 * x_align); y1 = ALIGN(y1, 2 * y_align); } else { x0 = ROUND_DOWN_TO(x0, x_align); y0 = ROUND_DOWN_TO(y0, y_align); x1 = ALIGN(x1, x_align); y1 = ALIGN(y1, y_align); } </div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> It fixes: <a href="https://bugs.freedesktop.org/show_bug.cgi?id=65744" target="_blank">https://bugs.freedesktop.org/show_bug.cgi?id=65744</a> Signed-off-by: Anuj Phogat <<a href="mailto:anuj.phogat@gmail.com">anuj.phogat@gmail.com</a>> --- Thanks Paul for your great help in figuring out the fix. src/mesa/drivers/dri/i965/brw_blorp_clear.cpp | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp b/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp index bf11135..2bebe8e 100644 --- a/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp +++ b/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp @@ -261,10 +261,14 @@ brw_blorp_clear_params::brw_blorp_clear_params(struct brw_context *brw, intel_get_non_msrt_mcs_alignment(intel, irb->mt, &x_align, &y_align); x_align *= 16; y_align *= 32; - x0 = ROUND_DOWN_TO(x0, x_align); - y0 = ROUND_DOWN_TO(y0, y_align); - x1 = ALIGN(x1, x_align); - y1 = ALIGN(y1, y_align); + /* For HSW GT3 clear rectangle must be aligned to two times the number + * of pixels in the table. + */ + + x0 = ROUND_DOWN_TO(x0, (intel->gen > 6 ? 2 * x_align : x_align)); + y0 = ROUND_DOWN_TO(y0, (intel->gen > 6 ? 2 * y_align : y_align)); + x1 = ALIGN(x1, (intel->gen > 6 ? 2 * x_align : x_align)); + y1 = ALIGN(y1, (intel->gen > 6 ? 2 * y_align : y_align)); /* From the Ivy Bridge PRM, Vol2 Part1 11.7 "MCS Buffer for Render * Target(s)", beneath the "Fast Color Clear" bullet (p327): -- 1.8.1.4 </blockquote></div> </div></div>