From: Tommi Rantala <tt.rantala@gmail.com>
Date: Fri, 3 Apr 2015 07:45:29 +0000 (+0300)
Subject: drm: fix drm_mode_getconnector() locking imbalance regression
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=04bdf441787a385487fb7b08d9a3f35a1271b474;p=openwrt%2Fstaging%2Fblogic.git

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>
---

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;