drm/i915: Markup potential lock for i915_active

Make the lockchains more deterministic via i915_active by flagging the
potential lock.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190703091726.11690-7-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 584b247df9bce9762a506ea9dfe07cafe50b5a42..13f304a29fc836dde7b7da1bf4b86d01d57630f4 100644 (file)
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -268,6 +268,8 @@ int i915_active_wait(struct i915_active *ref)
        int err;
 
        might_sleep();
+       might_lock(&ref->mutex);
+
        if (RB_EMPTY_ROOT(&ref->tree))
                return 0;