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

[jdhillon]

From: Roman Li <roman.li at 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 <lkp at intel.com>
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>

Reviewed-by: Wayne Lin <Wayne.Lin at amd.com>
Acked-by: Jasdeep Dhillon <jdhillon at amd.com>
Signed-off-by: Roman Li <roman.li at 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