[Intel-gfx] [PATCH v2] drm/i915: Warn on if set frontbuffer return value is not NULL on release

[Jouni Högander]

i915_gem_object_set_frontbuffer returns set frontbuffer pointer.  When we
are releasing frontbuffer we are clearing the pointer from the object. Warn
on if return value is not null.

v2: Instead of ignoring do drm_WARN_ON

Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>

Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
---
 drivers/gpu/drm/i915/display/intel_frontbuffer.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
index d5540c739404..95319301cf2b 100644
--- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c
+++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
@@ -259,7 +259,8 @@ static void frontbuffer_release(struct kref *ref)
 
 	i915_ggtt_clear_scanout(obj);
 
-	i915_gem_object_set_frontbuffer(obj, NULL);
+	drm_WARN_ON(&intel_bo_to_i915(obj)->drm,
+		    i915_gem_object_set_frontbuffer(obj, NULL) != NULL);
 	spin_unlock(&intel_bo_to_i915(obj)->display.fb_tracking.lock);
 
 	i915_active_fini(&front->write);
-- 
2.34.1