drm/mode: reduce lock hold in addfb2

No need to hold the lock while assigning the variable.

Daniel wrote:
"Not sure why exactly I put that under the lock, but the only thing that
can race here is rmfb while addfb2 is still doing it's thing, with a
correctly guess (easy to do since they're fully deterministic) fb_id."

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index b088840582cc..bbf7ce4ead99 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3445,11 +3445,11 @@ int drm_mode_addfb2(struct drm_device *dev,
         if (IS_ERR(fb))
                 return PTR_ERR(fb);
 
-        /* Transfer ownership to the filp for reaping on close */
-
         DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
-        mutex_lock(&file_priv->fbs_lock);
         r->fb_id = fb->base.id;
+
+        /* Transfer ownership to the filp for reaping on close */
+        mutex_lock(&file_priv->fbs_lock);
         list_add(&fb->filp_head, &file_priv->fbs);
         mutex_unlock(&file_priv->fbs_lock);