From 90754d2df05eafe1a3ee3cd9bb1611a19099fc49 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Wed, 3 Jun 2015 21:35:51 -0700 Subject: [PATCH] i965/gen9: Implement Push Constant Buffer workaround This implements a workaround (exact excerpt as a comment in the code). The docs specify [clearly, after you struggle for a while] that the offset isn't relative to state base. This actually makes sense. This fixes hangs on SKL. Buffer #0 is meant to be used for normal uniforms. Buffer #1 is typically used for gather constants when using RS. Buffer #1-#3 could be used to push a bunch of UBO data which would just be somewhere in memory, and not relative to the dynamic state. NOTE: I've moved away from the ternary operator for the new gen9 conditions. Admittedly it's probably not great to do this, but I really want to fix this all up in the subsequent patch and doing it here makes that diff a lot nicer. I want to split out the gen8/9 code to make the function a bit more readable, but to keep this easily cherry-pickable I am doing this fix first. If we decide not to merge the cleanup patch then I can revisit this. Cc: "10.5 10.6" Signed-off-by: Ben Widawsky Reviewed-by: Anuj Phogat Tested-by: Valtteri Rantala --- src/mesa/drivers/dri/i965/gen7_vs_state.c | 48 +++++++++++++++++++---- 1 file changed, 41 insertions(+), 7 deletions(-) diff --git a/src/mesa/drivers/dri/i965/gen7_vs_state.c b/src/mesa/drivers/dri/i965/gen7_vs_state.c index 278b3ec6d21..4b17d06fa83 100644 --- a/src/mesa/drivers/dri/i965/gen7_vs_state.c +++ b/src/mesa/drivers/dri/i965/gen7_vs_state.c @@ -43,18 +43,52 @@ gen7_upload_constant_state(struct brw_context *brw, int dwords = brw->gen >= 8 ? 11 : 7; BEGIN_BATCH(dwords); OUT_BATCH(opcode << 16 | (dwords - 2)); - OUT_BATCH(active ? stage_state->push_const_size : 0); - OUT_BATCH(0); + + /* Workaround for SKL+ (we use option #2 until we have a need for more + * constant buffers). This comes from the documentation for 3DSTATE_CONSTANT_* + * + * The driver must ensure The following case does not occur without a flush + * to the 3D engine: 3DSTATE_CONSTANT_* with buffer 3 read length equal to + * zero committed followed by a 3DSTATE_CONSTANT_* with buffer 0 read length + * not equal to zero committed. Possible ways to avoid this condition + * include: + * 1. always force buffer 3 to have a non zero read length + * 2. always force buffer 0 to a zero read length + */ + if (brw->gen >= 9 && active) { + OUT_BATCH(0); + OUT_BATCH(stage_state->push_const_size); + } else { + OUT_BATCH(active ? stage_state->push_const_size : 0); + OUT_BATCH(0); + } /* Pointer to the constant buffer. Covered by the set of state flags * from gen6_prepare_wm_contants */ - OUT_BATCH(active ? (stage_state->push_const_offset | mocs) : 0); - OUT_BATCH(0); - OUT_BATCH(0); - OUT_BATCH(0); - if (brw->gen >= 8) { + if (brw->gen >= 9 && active) { + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + /* XXX: When using buffers other than 0, you need to specify the + * graphics virtual address regardless of INSPM/debug bits + */ + OUT_RELOC64(brw->batch.bo, I915_GEM_DOMAIN_RENDER, 0, + stage_state->push_const_offset); OUT_BATCH(0); OUT_BATCH(0); + } else if (brw->gen>= 8) { + OUT_BATCH(active ? (stage_state->push_const_offset | mocs) : 0); + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + OUT_BATCH(0); + } else { + OUT_BATCH(active ? (stage_state->push_const_offset | mocs) : 0); + OUT_BATCH(0); OUT_BATCH(0); OUT_BATCH(0); } -- 2.30.2