test: Exercise concurrent GPU read/write with CPU domain access
Designed to exercise this patch to i915.ko:
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index fbf1118..57ae1f2 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3181,9 +3181,11 @@ i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_obj
if (ret)
return ret;
- ret = i915_gem_object_wait_rendering(obj);
- if (ret)
- return ret;
+ if (write || obj->pending_gpu_write) {
+ ret = i915_gem_object_wait_rendering(obj);
+ if (ret)
+ return ret;
+ }
i915_gem_object_flush_gtt_write_domain(obj);
By exercising the conditions whereby should either of the checks be missed
an error is detected.