Just looking for a quick patch review to make sure I've backported these patches to 8.0 correctly (and also confirmation that this backport is a good idea). These patches are intended to apply to the 8.0 branch.
The issue is that on Gen6 and Gen7, images rendered to depth and stencil buffers must be aligned to a multiple of 8 pixels, otherwise certain rendering operations produce a GPU hang. Unfortunately, due to the layout of miptrees (and the fact that we render to depth and stencil miptrees using coordinate offsets), it would take a lot of code rework to both produce correct rendering and guarantee no GPU hangs. These patches avoid the GPU hangs by forcing the image offsets to be multiples of 8. As a result, correct rendering to depth and stencil miptrees is sacrificed but the GPU doesn't hang. The sacrifice is minor, since it only affects miptree levels that would otherwise be unaligned (in practice this is usually just the smallest miplevels), and it only matters for (a) rendering to a depth/stencil buffer that is later used as a texture, or (b) ping-ponging between miplevels while rendering, both of which are fairly rare. On the master branch, we decided that this was a worthwhile compromise. As a result of this sacrifice, this will regress the following piglit tests: fbo/fbo-depth-array (Gen6 only), spec/ARB_depth_buffer_float/fbo-clear-formats, spec/ARB_depth_texture/fbo-clear-formats, and spec/EXT_packed_depth_stencil/fbo-clear-formats. These tests currently fail on master for the same reason. For more information see: https://bugs.freedesktop.org/show_bug.cgi?id=50271 [PATCH 1/2] i965/Gen6: Work around GPU hangs due to misaligned depth coordinate offsets. [PATCH 2/2] i965/Gen7: Work around GPU hangs due to misaligned depth coordinate offsets. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
