[bug report] drm/i915/dp: Add support for DP tunnel BW allocation

[Dan Carpenter]

Hello Imre Deak,

The patch 91888b5b1ad2: "drm/i915/dp: Add support for DP tunnel BW
allocation" from Feb 26, 2024 (linux-next), leads to the following
Smatch static checker warning:

	drivers/gpu/drm/i915/display/intel_dp_tunnel.c:793 intel_dp_tunnel_mgr_init()
	warn: 'tunnel_mgr' is not an error pointer

drivers/gpu/drm/i915/display/intel_dp_tunnel.c
    776 int intel_dp_tunnel_mgr_init(struct drm_i915_private *i915)
    777 {
    778         struct drm_dp_tunnel_mgr *tunnel_mgr;
    779         struct drm_connector_list_iter connector_list_iter;
    780         struct intel_connector *connector;
    781         int dp_connectors = 0;
    782 
    783         drm_connector_list_iter_begin(&i915->drm, &connector_list_iter);
    784         for_each_intel_connector_iter(connector, &connector_list_iter) {
    785                 if (connector->base.connector_type != DRM_MODE_CONNECTOR_DisplayPort)
    786                         continue;
    787 
    788                 dp_connectors++;
    789         }
    790         drm_connector_list_iter_end(&connector_list_iter);
    791 
    792         tunnel_mgr = drm_dp_tunnel_mgr_create(&i915->drm, dp_connectors);
--> 793         if (IS_ERR(tunnel_mgr))

The real implementation of drm_dp_tunnel_mgr_create() returns NULL but
the stub implementation returns ERR_PTR(-EOPNOTSUPP).

    794                 return PTR_ERR(tunnel_mgr);
    795 
    796         i915->display.dp_tunnel_mgr = tunnel_mgr;
    797 
    798         return 0;
    799 }

regards,
dan carpenter