drm: fix drm_mode_getconnector() locking imbalance regression

Regression in commit 2caa80e72b57c6216aec6f6a11fcfb4fec46daa0
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Feb 22 11:38:36 2015 +0100

    drm: Fix deadlock due to getconnector locking changes

If the drm_connector_find() call returns NULL, we should no longer
call drm_modeset_unlock() to avoid locking imbalance.

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 679b10e34fb5..b6f076b213bc 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2121,7 +2121,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
         connector = drm_connector_find(dev, out_resp->connector_id);
         if (!connector) {
                 ret = -ENOENT;
-                goto out;
+                goto out_unlock;
         }
 
         for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
@@ -2201,6 +2201,8 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 
 out:
         drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+out_unlock:
         mutex_unlock(&dev->mode_config.mutex);
 
         return ret;