drm/amd/display: Check engine is not NULL before acquiring

[ 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@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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 793c0cec407f9d36661216d55b55b0ba1fd3c6cd..5fcffb29317e354c1d02d22f7f1338cac374bc06 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
@@ -398,7 +398,7 @@ 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,