drm/amd/display: [MST] Fix startup sequence v3.

Problem: MST topology discovery was started before fbdev
init causing kernel panic on boot.
Fix: Defer MST to late init hook, after fbdev strucutres
already initilized.

v2: Add explicit late_init hook function in DAL.
v3:
Change signature of detect_mst_link_for_all_connectors
from void* to drm_dev*

Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 2a7802c..2af4ac0 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -367,27 +367,39 @@ static int dm_sw_fini(void *handle)
        return 0;
 }
 
-static void detect_link_for_all_connectors(struct drm_device *dev)
+static int detect_mst_link_for_all_connectors(struct drm_device *dev)
 {
        struct amdgpu_connector *aconnector;
        struct drm_connector *connector;
+       int ret = 0;
 
        drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 
        list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
                   aconnector = to_amdgpu_connector(connector);
-                  if (aconnector->dc_link->type == dc_connection_mst_branch) {
-                          DRM_INFO("DM_MST: starting TM on aconnector: %p [id: %d]\n",
-                                               aconnector, aconnector->base.base.id);
-
-                               if (drm_dp_mst_topology_mgr_set_mst(&aconnector->mst_mgr, true) < 0) {
-                                       DRM_ERROR("DM_MST: Failed to start MST\n");
-                                       ((struct dc_link *)aconnector->dc_link)->type = dc_connection_single;
+               if (aconnector->dc_link->type == dc_connection_mst_branch) {
+                       DRM_INFO("DM_MST: starting TM on aconnector: %p [id: %d]\n",
+                                       aconnector, aconnector->base.base.id);
+
+                       ret = drm_dp_mst_topology_mgr_set_mst(&aconnector->mst_mgr, true);
+                       if (ret < 0) {
+                               DRM_ERROR("DM_MST: Failed to start MST\n");
+                               ((struct dc_link *)aconnector->dc_link)->type = dc_connection_single;
+                               return ret;
                                }
-                  }
+                       }
        }
 
        drm_modeset_unlock(&dev->mode_config.connection_mutex);
+       return ret;
+}
+
+static int dm_late_init(void *handle)
+{
+       struct drm_device *dev = ((struct amdgpu_device *)handle)->ddev;
+       int r = detect_mst_link_for_all_connectors(dev);
+
+       return r;
 }
 
 static void s3_handle_mst(struct drm_device *dev, bool suspend)
@@ -417,11 +429,8 @@ static int dm_hw_init(void *handle)
        struct amdgpu_device *adev = (struct amdgpu_device *)handle;
        /* Create DAL display manager */
        amdgpu_dm_init(adev);
-
        amdgpu_dm_hpd_init(adev);
 
-       detect_link_for_all_connectors(adev->ddev);
-
        return 0;
 }
 
@@ -680,7 +689,7 @@ int amdgpu_dm_display_resume(struct amdgpu_device *adev )
 static const struct amd_ip_funcs amdgpu_dm_funcs = {
        .name = "dm",
        .early_init = dm_early_init,
-       .late_init = NULL,
+       .late_init = dm_late_init,
        .sw_init = dm_sw_init,
        .sw_fini = dm_sw_fini,
        .hw_init = dm_hw_init,