[PATCH AUTOSEL 5.5 24/58] drm/amd/display: Check engine is not NULL before acquiring

From: Sasha Levin
Date: Sat Feb 22 2020 - 21:36:27 EST


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 793c0cec407f9..5fcffb29317e3 100644
--- 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,
--
2.20.1