[PATCH RFC 22/33] drm: bridge: cdns-mhdp8546: Fix a locking bug in an error path

[Bart Van Assche]

Do not unlock mhdp->mbox_mutex if it has not been locked.

This bug has been detected by the Clang thread-safety analyzer.

Cc: Swapnil Jakhade <sjakhade@xxxxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Fixes: fb43aa0acdfd ("drm: bridge: Add support for Cadence MHDP8546 DPI/DP bridge")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
index d081850e3c03..9295b2a9f9be 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
@@ -502,8 +502,7 @@ int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp, unsigned int nlanes,
 
 	if (nlanes != 4 && nlanes != 2 && nlanes != 1) {
 		dev_err(mhdp->dev, "invalid number of lanes: %u\n", nlanes);
-		ret = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	payload[0] = nlanes;