diff options
authorKenneth Graunke <>2017-07-01 01:55:52 -0700
committerKenneth Graunke <>2017-07-10 15:55:34 -0700
commit7250cbafb90271579a1d07160498e902996cbc97 (patch)
parentde4c2eaa627204ffa54160ab9ea0bd3aaf3732b2 (diff)
i965: Assert that we don't use CPU write maps to non-coherent buffers.cros-mesa-17.1.1-r3-vanillachadv/cros-mesa-17.1.1-r3-vanilla
Using CPU maps of non-coherent buffers can get us in a lot of trouble, and WC maps are a reasonable alternative anyway. Guard against shooting ourselves in the foot by adding an assert, and comment. Reviewed-by: Chris Wilson <> Reviewed-by: Matt Turner <>
1 files changed, 6 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.c b/src/mesa/drivers/dri/i965/brw_bufmgr.c
index d9b37bfae34..11251f15edc 100644
--- a/src/mesa/drivers/dri/i965/brw_bufmgr.c
+++ b/src/mesa/drivers/dri/i965/brw_bufmgr.c
@@ -669,6 +669,12 @@ brw_bo_map_cpu(struct brw_context *brw, struct brw_bo *bo, unsigned flags)
struct brw_bufmgr *bufmgr = bo->bufmgr;
+ /* We disallow CPU maps for writing to non-coherent buffers, as the
+ * CPU map can become invalidated when a batch is flushed out, which
+ * can happen at unpredictable times. You should use WC maps instead.
+ */
+ assert(bo->cache_coherent || !(flags & MAP_WRITE));
if (!bo->map_cpu) {
struct drm_i915_gem_mmap mmap_arg;
void *map;