drm: fix drm_mode_getconnector() locking imbalance regression

Regression in commit 2caa80e72b57c6216aec6f6a11fcfb4fec46daa0
Author: Daniel Vetter <[email protected]>
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 <[email protected]>
Cc: Daniel Vetter <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 679b10e34fb545f23c827f9699bfef1c9f4268bd..b6f076b213bcfde496a61824335b68d1760b5613 100644 (file)
--- 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;