drm/i915: Check locking in i915_gem_request_unreference
With refcounting it looks like you can just drop that refcount, but
that's not really the case. So make sure no one forgets.
Motivated by the unlocked call in the mmio flip code.
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Thomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 23a1afd..9a9372a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2046,6 +2046,7 @@
static inline void
i915_gem_request_unreference(struct drm_i915_gem_request *req)
{
+ WARN_ON(!mutex_is_locked(&req->ring->dev->struct_mutex));
kref_put(&req->ref, i915_gem_request_free);
}