drm/client: Do not free client memory by default

Make no assumption on the allocation of the client's memory. For
example, amdgpu stores a client within another data structures,
where it cannot be freed by itself.

The correct place to free the client's memory is the client's free
callback. All existing clients implement this.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20251009132006.45834-5-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/drm_client_event.c

@@ -39,12 +39,13 @@ void drm_client_dev_unregister(struct drm_device *dev)
 	mutex_lock(&dev->clientlist_mutex);
 	list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
 		list_del(&client->list);
-		if (client->funcs && client->funcs->unregister) {
+		/*
+		 * Unregistering consumes and frees the client.
+		 */
+		if (client->funcs && client->funcs->unregister)
 			client->funcs->unregister(client);
-		} else {
+		else
 			drm_client_release(client);
-			kfree(client);
-		}
 	}
 	mutex_unlock(&dev->clientlist_mutex);
 }