[PATCH 1/3] drm/dp/mst: Handle errors from drm_atomic_get_private_obj_state() correctly

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

On failure drm_atomic_get_private_obj_state() returns and error
pointer instead of NULL. Adjust the checks in the callers to match.

Cc: stable at vger.kernel.org
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Fixes: edb1ed1ab7d3 ("drm/dp: Add DP MST helpers to atomically find and release vcpi slots")
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index bfd237c15e76..18cecd94acb6 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2515,8 +2515,8 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
 	int req_slots;
 
 	topology_state = drm_atomic_get_mst_topology_state(state, mgr);
-	if (topology_state == NULL)
-		return -ENOMEM;
+	if (IS_ERR(topology_state))
+		return PTR_ERR(topology_state);
 
 	port = drm_dp_get_validated_port_ref(mgr, port);
 	if (port == NULL)
@@ -2555,8 +2555,8 @@ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
 	struct drm_dp_mst_topology_state *topology_state;
 
 	topology_state = drm_atomic_get_mst_topology_state(state, mgr);
-	if (topology_state == NULL)
-		return -ENOMEM;
+	if (IS_ERR(topology_state))
+		return PTR_ERR(topology_state);
 
 	/* We cannot rely on port->vcpi.num_slots to update
 	 * topology_state->avail_slots as the port may not exist if the parent
-- 
2.13.0