[PATCH 22/50] drm/amd/display: Check stream before comparing them

[Fangzhi Zuo]

From: Alex Hung <alex.hung at amd.com>

[WHAT & HOW]
amdgpu_dm can pass a null stream to dc_is_stream_unchanged. It is
necessary to check for null before dereferencing them.

This fixes 1 FORWARD_NULL issue reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo at amd.com>
Signed-off-by: Alex Hung <alex.hung at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index bcb5267b5a6b..83aa3d8a997a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -3241,6 +3241,8 @@ static bool are_stream_backends_same(
 bool dc_is_stream_unchanged(
 	struct dc_stream_state *old_stream, struct dc_stream_state *stream)
 {
+	if (!old_stream || !stream)
+		return false;
 
 	if (!are_stream_backends_same(old_stream, stream))
 		return false;
-- 
2.34.1