From 8a9491058da72ee2df75da25bb147010a451fb68 Mon Sep 17 00:00:00 2001 From: Nanley Chery Date: Wed, 2 May 2018 09:38:47 -0700 Subject: [PATCH] i965/miptree: Zero-initialize CCS_D buffers Before this patch, the aux_state was actually AUX_INVALID because the BO was never defined. This was fine on single slice miptrees because we would fast-clear the resource right after creation. For multi-slice miptrees on SKL+ however, this results in undefined behavior when accessing a non-base slice. Here's a specific example: 1) Fast clear level 0 * Undefined CCS_D buffer allocated in "PASS_THROUGH" state. * Level 0 transitions to the CLEAR state. 2) Render to level 1 * Level 1 may have a 2-bit pattern of 2's. * Rendering with a 2 in the CCS is undefined. Cc: Reviewed-by: Jason Ekstrand --- src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c index dd851ff9b5c..c01a71d4453 100644 --- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c +++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c @@ -1801,13 +1801,11 @@ intel_miptree_alloc_ccs(struct brw_context *brw, * A CCS value of 0 indicates that the corresponding block is in the * pass-through state which is what we want. * - * For CCS_D, on the other hand, we don't care as we're about to perform a - * fast-clear operation. In that case, being hot in caches more useful. + * For CCS_D, do the same thing. On gen9+, this avoids having any undefined + * bits in the aux buffer. */ - const uint32_t alloc_flags = mt->aux_usage == ISL_AUX_USAGE_CCS_E ? - BO_ALLOC_ZEROED : BO_ALLOC_BUSY; - mt->aux_buf = intel_alloc_aux_buffer(brw, "ccs-miptree", - &temp_ccs_surf, alloc_flags, mt); + mt->aux_buf = intel_alloc_aux_buffer(brw, "ccs-miptree", &temp_ccs_surf, + BO_ALLOC_ZEROED, mt); if (!mt->aux_buf) { free(aux_state); return false; -- 2.30.2