[PATCH 17/23] drm/amd/display: Fix potential null-deref in dm_resume

[jdhillon]

From: Roman Li <roman...@amd.com>

[Why]
Fixing smatch error:
dm_resume() error: we previously assumed 'aconnector->dc_link' could be null

[How]
Check if dc_link null at the beginning of the loop,
so further checks can be dropped.

Reported-by: kernel test robot <l...@intel.com>
Reported-by: Dan Carpenter <dan.carpen...@oracle.com>

Reviewed-by: Wayne Lin <wayne....@amd.com>
Acked-by: Jasdeep Dhillon <jdhil...@amd.com>
Signed-off-by: Roman Li <roman...@amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 37c6be337a85..88474f04fa9a 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2739,12 +2739,14 @@ static int dm_resume(void *handle)
        drm_for_each_connector_iter(connector, &iter) {
                aconnector = to_amdgpu_dm_connector(connector);
 
+               if (!aconnector->dc_link)
+                       continue;
+
                /*
                 * this is the case when traversing through already created
                 * MST connectors, should be skipped
                 */
-               if (aconnector->dc_link &&
-                   aconnector->dc_link->type == dc_connection_mst_branch)
+               if (aconnector->dc_link->type == dc_connection_mst_branch)
                        continue;
 
                mutex_lock(&aconnector->hpd_lock);
-- 
2.34.1