[PATCH] drm: bridge: cdns-mhdp8546: Fix missing mutex unlock on error path

[Aleksandr Mishin]

In cdns_mhdp_atomic_enable(), there is an error return on failure of
drm_mode_duplicate() which leads to the mutex remaining locked.
Add a mutex unlock call.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 935a92a1c400 ("drm: bridge: cdns-mhdp8546: Fix possible null pointer dereference")
Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
---
This patch is against drm-misc-next branch of drm-misc repo.

 drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 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 8a91ef0ae065..65a4bd09d9c6 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
@@ -2059,8 +2059,10 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge,
 	mhdp_state = to_cdns_mhdp_bridge_state(new_state);
 
 	mhdp_state->current_mode = drm_mode_duplicate(bridge->dev, mode);
-	if (!mhdp_state->current_mode)
-		return;
+	if (!mhdp_state->current_mode) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	drm_mode_set_name(mhdp_state->current_mode);
 
-- 
2.30.2