drm/amd/display: Fix MST daisy chain SST not light up

In SST daisy chain scenario, edid is getting read in mst hotplug
routine. It is getting conflict with drm send_enum_path_resources
kernel thread in terms of i2c bus which is getting locked up in
such case.

Have edid being read in get_mode hook, instead of in hotplug
routine.

Signed-off-by: Jerry Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index dfcfb5a..610375b 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -174,14 +174,60 @@ static const struct drm_connector_funcs dm_dp_mst_connector_funcs = {
        .atomic_get_property = amdgpu_dm_connector_atomic_get_property
 };
 
+static int dm_connector_update_modes(struct drm_connector *connector,
+                               struct edid *edid)
+{
+       int ret;
+
+       ret = drm_add_edid_modes(connector, edid);
+       drm_edid_to_eld(connector, edid);
+
+       return ret;
+}
+
 static int dm_dp_mst_get_modes(struct drm_connector *connector)
 {
        struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
        int ret = 0;
 
-       ret = drm_add_edid_modes(&aconnector->base, aconnector->edid);
+       if (!aconnector)
+               return dm_connector_update_modes(connector, NULL);
+
+       if (!aconnector->edid) {
+               struct edid *edid;
+               struct dc_sink *dc_sink;
+               struct dc_sink_init_data init_params = {
+                               .link = aconnector->dc_link,
+                               .sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST };
+               edid = drm_dp_mst_get_edid(connector, &aconnector->mst_port->mst_mgr, aconnector->port);
 
-       drm_edid_to_eld(&aconnector->base, aconnector->edid);
+               if (!edid) {
+                       drm_mode_connector_update_edid_property(
+                               &aconnector->base,
+                               NULL);
+                       return ret;
+               }
+
+               aconnector->edid = edid;
+
+               dc_sink = dc_link_add_remote_sink(
+                       aconnector->dc_link,
+                       (uint8_t *)edid,
+                       (edid->extensions + 1) * EDID_LENGTH,
+                       &init_params);
+
+               dc_sink->priv = aconnector;
+               aconnector->dc_sink = dc_sink;
+
+               if (aconnector->dc_sink)
+                       amdgpu_dm_add_sink_to_freesync_module(
+                                       connector, edid);
+
+               drm_mode_connector_update_edid_property(
+                                               &aconnector->base, edid);
+       }
+
+       ret = dm_connector_update_modes(connector, aconnector->edid);
 
        return ret;
 }
@@ -343,66 +389,8 @@ static void dm_dp_mst_hotplug(struct drm_dp_mst_topology_mgr *mgr)
 {
        struct amdgpu_dm_connector *master = container_of(mgr, struct amdgpu_dm_connector, mst_mgr);
        struct drm_device *dev = master->base.dev;
-       struct amdgpu_device *adev = dev->dev_private;
-       struct drm_connector *connector;
-       struct amdgpu_dm_connector *aconnector;
-       struct edid *edid;
-       struct dc_sink *dc_sink;
-
-       drm_modeset_lock_all(dev);
-       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-               aconnector = to_amdgpu_dm_connector(connector);
-               if (aconnector->port &&
-                               aconnector->port->pdt != DP_PEER_DEVICE_NONE &&
-                               aconnector->port->pdt != DP_PEER_DEVICE_MST_BRANCHING &&
-                               !aconnector->dc_sink) {
-                       /*
-                        * This is plug in case, where port has been created but
-                        * sink hasn't been created yet
-                        */
-                       if (!aconnector->edid) {
-                               struct dc_sink_init_data init_params = {
-                                               .link = aconnector->dc_link,
-                                               .sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST};
-                               edid = drm_dp_mst_get_edid(connector, &aconnector->mst_port->mst_mgr, aconnector->port);
-
-                               if (!edid) {
-                                       drm_mode_connector_update_edid_property(
-                                               &aconnector->base,
-                                               NULL);
-                                       continue;
-                               }
-
-                               aconnector->edid = edid;
-
-                               dc_sink = dc_link_add_remote_sink(
-                                       aconnector->dc_link,
-                                       (uint8_t *)edid,
-                                       (edid->extensions + 1) * EDID_LENGTH,
-                                       &init_params);
-
-                               dc_sink->priv = aconnector;
-                               aconnector->dc_sink = dc_sink;
-
-                               if (aconnector->dc_sink)
-                                       amdgpu_dm_add_sink_to_freesync_module(
-                                                       connector,
-                                                       edid);
-
-                               dm_restore_drm_connector_state(connector->dev, connector);
-                       } else
-                               edid = aconnector->edid;
-
-                       DRM_DEBUG_KMS("edid retrieved %p\n", edid);
-
-                       drm_mode_connector_update_edid_property(
-                               &aconnector->base,
-                               aconnector->edid);
-               }
-       }
-       drm_modeset_unlock_all(dev);
 
-       schedule_work(&adev->dm.mst_hotplug_work);
+       drm_kms_helper_hotplug_event(dev);
 }
 
 static void dm_dp_mst_register_connector(struct drm_connector *connector)