[PATCH] drm/amd/display: Handle null 'stream_status' in 'planes_changed_for_existing_stream'

[Srinivasan Shanmugam]

This commit adds a null check for 'stream_status' in the function
'planes_changed_for_existing_stream'. Previously, the code assumed
'stream_status' could be null, but did not handle the case where it was
actually null. This could lead to a null pointer dereference.

Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_resource.c:3784 
planes_changed_for_existing_stream() error: we previously assumed 
'stream_status' could be null (see line 3774)

Cc: Tom Chung <chiahsuan.ch...@amd.com>
Cc: Rodrigo Siqueira <rodrigo.sique...@amd.com>
Cc: Roman Li <roman...@amd.com>
Cc: Alex Hung <alex.h...@amd.com>
Cc: Aurabindo Pillai <aurabindo.pil...@amd.com>
Cc: Harry Wentland <harry.wentl...@amd.com>
Cc: Hamza Mahfooz <hamza.mahf...@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

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 5c9091f2a8b2..60d34c696b18 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -3771,8 +3771,10 @@ static bool planes_changed_for_existing_stream(struct 
dc_state *context,
                }
        }
 
-       if (!stream_status)
+       if (!stream_status) {
                ASSERT(0);
+               return false;
+       }
 
        for (i = 0; i < set_count; i++)
                if (set[i].stream == stream)
-- 
2.34.1