Starting with GEN8, there is documentation that the multisample state command must be emitted before the 3DSTATE_WM_HZ_OP command any time the multisample count changes. The 3DSTATE_WM_HZ_OP packet gets emitted as a result of a intel_hix_exec(), which is called upon a fast clear and/or a resolve. This can happen before the state atoms are checked, and so the multisample state must be put directly in the function.
v1: - In v0, I was always emitting the command, but Ken came up with the condition to determine whether or not the sample count actually changed. - Ken's recommendation was to set brw->num_multisamples after emitting 3DSTATE_MULTISAMPLE. This doesn't work. I put my best guess as to why in the XXX (it was causing 7 regressions on BDW). Jenkins results: http://otc-mesa-ci.jf.intel.com/view/dev/job/bwidawsk/136/ Fixes around 200 piglit tests on SKL. I'm somewhat surprised that it seems to have no impact on BDW as the restriction is needed there as well. Cc: mesa-sta...@lists.freedesktop.org Cc: Anuj Phogat <anuj.pho...@intel.com> Cc: Kenneth Graunke <kenn...@whitecape.org> Signed-off-by: Ben Widawsky <b...@bwidawsk.net> Reviewed-by: Neil Roberts <n...@linux.intel.com> --- src/mesa/drivers/dri/i965/gen8_depth_state.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/mesa/drivers/dri/i965/gen8_depth_state.c b/src/mesa/drivers/dri/i965/gen8_depth_state.c index b502650..4888dad 100644 --- a/src/mesa/drivers/dri/i965/gen8_depth_state.c +++ b/src/mesa/drivers/dri/i965/gen8_depth_state.c @@ -417,6 +417,18 @@ gen8_hiz_exec(struct brw_context *brw, struct intel_mipmap_tree *mt, uint32_t surface_width = ALIGN(mt->logical_width0, level == 0 ? 8 : 1); uint32_t surface_height = ALIGN(mt->logical_height0, level == 0 ? 4 : 1); + /* From the documentation for 3DSTATE_WM_HZ_OP: "3DSTATE_MULTISAMPLE packet + * must be used prior to this packet to change the Number of Multisamples. + * This packet must not be used to change Number of Multisamples in a + * rendering sequence." + * + * XXX: It's temping to set brw->num_samples at this point but we cannot as + * there may be functions later in the state setup which needs to know of the + * change (intel_miptree_match_image). + */ + if (brw->num_samples != mt->num_samples) + gen8_emit_3dstate_multisample(brw, mt->num_samples); + /* The basic algorithm is: * - If needed, emit 3DSTATE_{DEPTH,HIER_DEPTH,STENCIL}_BUFFER and * 3DSTATE_CLEAR_PARAMS packets to set up the relevant buffers. -- 2.4.1 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
