[PATCH 09/62] drm: bridge: cdns-mhdp8546: Fix a locking bug in an error path

[Bart Van Assche <bart.vanassche@linux.dev>]

From: Bart Van Assche <bvanassche@acm.org>

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

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

Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Robert Foss <rfoss@kernel.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Swapnil Jakhade <sjakhade@cadence.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Fixes: fb43aa0acdfd ("drm: bridge: Add support for Cadence MHDP8546 DPI/DP bridge")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 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 9392c226ff5b..ce4516de11d8 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;