drm/debugfs: create debugfs late register functions

Although the device-centered debugfs functions can track requests for
the addition of DRM debugfs files at any time and have them added all
at once during drm_dev_register(), they are not able to create debugfs
files for modeset components, as they are registered after the primary
and the render drm_minor are registered.

So, create a drm_debugfs_late_register() function, which is responsible
for dealing with the creation of all the debugfs files for modeset
components at once. Therefore, the functions drm_debugfs_add_file()
and drm_debugfs_add_files() can be used in late_register hooks.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-4-mcanal@igalia.com

drivers/gpu/drm/drm_debugfs.c

@@ -254,6 +254,20 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 	return 0;
 }
 
+void drm_debugfs_late_register(struct drm_device *dev)
+{
+	struct drm_minor *minor = dev->primary;
+	struct drm_debugfs_entry *entry, *tmp;
+
+	if (!minor)
+		return;
+
+	list_for_each_entry_safe(entry, tmp, &dev->debugfs_list, list) {
+		debugfs_create_file(entry->file.name, S_IFREG | S_IRUGO,
+				    minor->debugfs_root, entry, &drm_debugfs_entry_fops);
+		list_del(&entry->list);
+	}
+}
 
 int drm_debugfs_remove_files(const struct drm_info_list *files, int count,
 			     struct drm_minor *minor)

drivers/gpu/drm/drm_internal.h

@@ -186,6 +186,7 @@ int drm_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
 int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 		     struct dentry *root);
 void drm_debugfs_cleanup(struct drm_minor *minor);
+void drm_debugfs_late_register(struct drm_device *dev);
 void drm_debugfs_connector_add(struct drm_connector *connector);
 void drm_debugfs_connector_remove(struct drm_connector *connector);
 void drm_debugfs_crtc_add(struct drm_crtc *crtc);
@@ -202,6 +203,10 @@ static inline void drm_debugfs_cleanup(struct drm_minor *minor)
 {
 }
 
+static inline void drm_debugfs_late_register(struct drm_device *dev)
+{
+}
+
 static inline void drm_debugfs_connector_add(struct drm_connector *connector)
 {
 }

drivers/gpu/drm/drm_mode_config.c

@@ -54,6 +54,8 @@ int drm_modeset_register_all(struct drm_device *dev)
 	if (ret)
 		goto err_connector;
 
+	drm_debugfs_late_register(dev);
+
 	return 0;
 
 err_connector: