Commit 7a90f899 authored Dec 13, 2019 by Chris Wilson

drm/i915/gem: Serialise object before changing cache-level

Wait for the object to be idle before changing its cache-level and
unbinding. This was dropped as supposedly superfluous from commit
8b1c78e0 ("drm/i915: Avoid calling i915_gem_object_unbind holding
object lock"), but it turns out to prevent some cache dirt escaping.
Smells like papering over a race...

Closes: https://gitlab.freedesktop.org/drm/intel/issues/820

Fixes: 8b1c78e0 ("drm/i915: Avoid calling i915_gem_object_unbind holding object lock")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213223140.1830738-1-chris@chris-wilson.co.uk

parent 9c569784

drivers/gpu/drm/i915/gem/i915_gem_domain.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -190,6 +190,13 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
		if (obj->cache_level == cache_level)
		return 0;

		ret = i915_gem_object_wait(obj,
		I915_WAIT_INTERRUPTIBLE \|
		I915_WAIT_ALL,
		MAX_SCHEDULE_TIMEOUT);
		if (ret)
		return ret;

		ret = i915_gem_object_lock_interruptible(obj);
		if (ret)
		return ret;