[PATCH AUTOSEL 5.4 23/50] drm/amd/display: Check engine is not NULL before acquiring

[Sasha Levin]

From: Aric Cyr <aric.cyr@xxxxxxx>

[ Upstream commit 2b63d0ec0daf79ba503fa8bfa25e07dc3da274f3 ]

[Why]
Engine can be NULL in some cases, so we must not acquire it.

[How]
Check for NULL engine before acquiring.

Signed-off-by: Aric Cyr <aric.cyr@xxxxxxx>
Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
index c3f9f4185ce8d..cf877238fff9d 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
@@ -386,7 +386,7 @@ static bool acquire(
 {
 	enum gpio_result result;
 
-	if (!is_engine_available(engine))
+	if ((engine == NULL) || !is_engine_available(engine))
 		return false;
 
 	result = dal_ddc_open(ddc, GPIO_MODE_HARDWARE,
-- 
2.20.1