[PATCH 3/3] drm/amd/display: Add NULL check for function pointer in dcn401_set_output_transfer_func

[Srinivasan Shanmugam]

This commit adds a null check for the set_output_gamma function pointer
in the dcn401_set_output_transfer_func function. Previously,
set_output_gamma was being checked for null, but then it was being
dereferenced without any null check. This could lead to a null pointer
dereference if set_output_gamma is null.

To fix this, we now ensure that set_output_gamma is not null before
dereferencing it. We do this by adding a null check for set_output_gamma
before the call to set_output_gamma.

Cc: Tom Chung <chiahsuan.chung at amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
Cc: Roman Li <roman.li at amd.com>
Cc: Alex Hung <alex.hung at amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai at amd.com>
Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Hamza Mahfooz <hamza.mahfooz at amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>
---
 drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
index ceaaa8df3641..77489bbcda02 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
@@ -743,7 +743,9 @@ bool dcn401_set_output_transfer_func(struct dc *dc,
 		}
 	}
 
-	mpc->funcs->set_output_gamma(mpc, mpcc_id, params);
+	if (mpc->funcs->set_output_gamma)
+		mpc->funcs->set_output_gamma(mpc, mpcc_id, params);
+
 	return ret;
 }
 
-- 
2.34.1