From 6c39ae2ecdb30cec4a2bd320926c839d5c0ec9cc Mon Sep 17 00:00:00 2001
From: Leo Li <sunpeng.li@amd.com>
Date: Thu, 6 Jun 2019 15:02:42 -0400
Subject: [PATCH] Fixing driver unload with mst devices

Signed-off-by: Leo Li <sunpeng.li@amd.com>
---
 drivers/gpu/drm/drm_dp_helper.c       | 12 ++++++++++++
 drivers/gpu/drm/drm_dp_mst_topology.c |  7 -------
 drivers/gpu/drm/i915/intel_dp_mst.c   | 33 +++++++++++++++++++++++++++++++--
 include/drm/drm_dp_helper.h           |  2 ++
 4 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index e6af758..4de68ea 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1174,6 +1174,18 @@ void drm_dp_aux_unregister(struct drm_dp_aux *aux)
 }
 EXPORT_SYMBOL(drm_dp_aux_unregister);

+int drm_dp_remote_aux_register(struct drm_dp_aux *aux)
+{
+   return drm_dp_aux_register_devnode(aux);
+}
+EXPORT_SYMBOL(drm_dp_remote_aux_register);
+
+void drm_dp_remote_aux_unregister(struct drm_dp_aux *aux)
+{
+   drm_dp_aux_unregister_devnode(aux);
+}
+EXPORT_SYMBOL(drm_dp_remote_aux_unregister);
+
 #define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x)

 /**
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 3829f54..a85f055 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1243,7 +1243,6 @@ static void drm_dp_destroy_port(struct kref *kref)
    struct drm_dp_mst_topology_mgr *mgr = port->mgr;

    if (!port->input) {
-       drm_dp_aux_unregister_devnode(&port->aux);

        port->vcpi.num_slots = 0;

@@ -1675,12 +1674,6 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
            drm_connector_set_tile_property(port->connector);
        }
        (*mstb->mgr->cbs->register_connector)(port->connector);
-
-       if (port->connector->registration_state ==
-           DRM_CONNECTOR_REGISTERED)
-           port->aux.dev = port->connector->kdev;
-
-       drm_dp_aux_register_devnode(&port->aux);
    }

 out:
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 0caf645..a3d9bc7 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -399,13 +399,42 @@ intel_dp_mst_detect(struct drm_connector *connector, bool force)
                      intel_connector->port);
 }

+static int
+intel_dp_mst_connector_late_register(struct drm_connector *connector)
+{
+   struct intel_connector *intel_connector = to_intel_connector(connector);
+   struct drm_dp_mst_port *port = intel_connector->port;
+
+   int ret;
+
+   ret = intel_connector_register(connector);
+   if (ret)
+       return ret;
+
+   DRM_DEBUG_KMS("registering %s MST bus for %s\n",
+             port->aux.name, connector->kdev->kobj.name);
+
+   port->aux.dev = connector->kdev;
+   return drm_dp_remote_aux_register(&port->aux);
+}
+
+static void
+intel_dp_mst_connector_early_unregister(struct drm_connector *connector)
+{
+   struct intel_connector *intel_connector = to_intel_connector(connector);
+   struct drm_dp_mst_port *port = intel_connector->port;
+
+   drm_dp_remote_aux_unregister(&port->aux);
+   intel_connector_unregister(connector);
+}
+
 static const struct drm_connector_funcs intel_dp_mst_connector_funcs = {
    .detect = intel_dp_mst_detect,
    .fill_modes = drm_helper_probe_single_connector_modes,
    .atomic_get_property = intel_digital_connector_atomic_get_property,
    .atomic_set_property = intel_digital_connector_atomic_set_property,
-   .late_register = intel_connector_register,
-   .early_unregister = intel_connector_unregister,
+   .late_register = intel_dp_mst_connector_late_register,
+   .early_unregister = intel_dp_mst_connector_early_unregister,
    .destroy = intel_connector_destroy,
    .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
    .atomic_duplicate_state = intel_digital_connector_duplicate_state,
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index efd14b8..d086897 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1371,6 +1371,8 @@ void drm_dp_downstream_debug(struct seq_file *m, const u8 dpcd[DP_RECEIVER_CAP_S
 void drm_dp_aux_init(struct drm_dp_aux *aux);
 int drm_dp_aux_register(struct drm_dp_aux *aux);
 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
+int drm_dp_remote_aux_register(struct drm_dp_aux *aux);
+void drm_dp_remote_aux_unregister(struct drm_dp_aux *aux);

 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc);
 int drm_dp_stop_crc(struct drm_dp_aux *aux);
--
2.7.4