Input: serio - make serio_register_driver() return errors

Perform actual driver registration right in serio_register_driver()
instead of offloading it to kseriod and return proper error code to
callers if driver registration fails.

Note that driver <-> port matching is still done by kseriod to
speed up boot process since probing for PS/2 mice and keyboards
is pretty slow.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 75 insertions, 39 deletions

diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index cd55ddb7df4f..8c717042f611 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -44,7 +44,7 @@ EXPORT_SYMBOL(serio_interrupt);
 EXPORT_SYMBOL(__serio_register_port);
 EXPORT_SYMBOL(serio_unregister_port);
 EXPORT_SYMBOL(serio_unregister_child_port);
-EXPORT_SYMBOL(__serio_register_driver);
+EXPORT_SYMBOL(serio_register_driver);
 EXPORT_SYMBOL(serio_unregister_driver);
 EXPORT_SYMBOL(serio_open);
 EXPORT_SYMBOL(serio_close);
@@ -61,10 +61,10 @@ static LIST_HEAD(serio_list);
 
 static struct bus_type serio_bus;
 
-static void serio_add_driver(struct serio_driver *drv);
 static void serio_add_port(struct serio *serio);
 static void serio_reconnect_port(struct serio *serio);
 static void serio_disconnect_port(struct serio *serio);
+static void serio_attach_driver(struct serio_driver *drv);
 
 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
 {
@@ -168,10 +168,10 @@ static void serio_find_driver(struct serio *serio)
  */
 
 enum serio_event_type {
-        SERIO_RESCAN,
-        SERIO_RECONNECT,
+        SERIO_RESCAN_PORT,
+        SERIO_RECONNECT_PORT,
         SERIO_REGISTER_PORT,
-        SERIO_REGISTER_DRIVER,
+        SERIO_ATTACH_DRIVER,
 };
 
 struct serio_event {
@@ -186,11 +186,12 @@ static LIST_HEAD(serio_event_list);
 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 static struct task_struct *serio_task;
 
-static void serio_queue_event(void *object, struct module *owner,
-                              enum serio_event_type event_type)
+static int serio_queue_event(void *object, struct module *owner,
+                             enum serio_event_type event_type)
 {
         unsigned long flags;
         struct serio_event *event;
+        int retval = 0;
 
         spin_lock_irqsave(&serio_event_lock, flags);
 
@@ -209,24 +210,34 @@ static void serio_queue_event(void *object, struct module *owner,
                 }
         }
 
-        if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
-                if (!try_module_get(owner)) {
-                        printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
-                        kfree(event);
-                        goto out;
-                }
-
-                event->type = event_type;
-                event->object = object;
-                event->owner = owner;
+        event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
+        if (!event) {
+                printk(KERN_ERR
+                        "serio: Not enough memory to queue event %d\n",
+                        event_type);
+                retval = -ENOMEM;
+                goto out;
+        }
 
-                list_add_tail(&event->node, &serio_event_list);
-                wake_up(&serio_wait);
-        } else {
-                printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
+        if (!try_module_get(owner)) {
+                printk(KERN_WARNING
+                        "serio: Can't get module reference, dropping event %d\n",
+                        event_type);
+                kfree(event);
+                retval = -EINVAL;
+                goto out;
         }
+
+        event->type = event_type;
+        event->object = object;
+        event->owner = owner;
+
+        list_add_tail(&event->node, &serio_event_list);
+        wake_up(&serio_wait);
+
 out:
         spin_unlock_irqrestore(&serio_event_lock, flags);
+        return retval;
 }
 
 static void serio_free_event(struct serio_event *event)
@@ -304,17 +315,17 @@ static void serio_handle_event(void)
                                 serio_add_port(event->object);
                                 break;
 
-                        case SERIO_RECONNECT:
+                        case SERIO_RECONNECT_PORT:
                                 serio_reconnect_port(event->object);
                                 break;
 
-                        case SERIO_RESCAN:
+                        case SERIO_RESCAN_PORT:
                                 serio_disconnect_port(event->object);
                                 serio_find_driver(event->object);
                                 break;
 
-                        case SERIO_REGISTER_DRIVER:
-                                serio_add_driver(event->object);
+                        case SERIO_ATTACH_DRIVER:
+                                serio_attach_driver(event->object);
                                 break;
 
                         default:
@@ -666,12 +677,12 @@ static void serio_disconnect_port(struct serio *serio)
 
 void serio_rescan(struct serio *serio)
 {
-        serio_queue_event(serio, NULL, SERIO_RESCAN);
+        serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
 }
 
 void serio_reconnect(struct serio *serio)
 {
-        serio_queue_event(serio, NULL, SERIO_RECONNECT);
+        serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
 }
 
 /*
@@ -766,22 +777,52 @@ static int serio_driver_remove(struct device *dev)
         return 0;
 }
 
-static void serio_add_driver(struct serio_driver *drv)
+static void serio_attach_driver(struct serio_driver *drv)
 {
         int error;
 
-        error = driver_register(&drv->driver);
+        error = driver_attach(&drv->driver);
         if (error)
-                printk(KERN_ERR
-                        "serio: driver_register() failed for %s, error: %d\n",
+                printk(KERN_WARNING
+                        "serio: driver_attach() failed for %s with error %d\n",
                         drv->driver.name, error);
 }
 
-void __serio_register_driver(struct serio_driver *drv, struct module *owner)
+int serio_register_driver(struct serio_driver *drv)
 {
+        int manual_bind = drv->manual_bind;
+        int error;
+
         drv->driver.bus = &serio_bus;
 
-        serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
+        /*
+         * Temporarily disable automatic binding because probing
+         * takes long time and we are better off doing it in kseriod
+         */
+        drv->manual_bind = 1;
+
+        error = driver_register(&drv->driver);
+        if (error) {
+                printk(KERN_ERR
+                        "serio: driver_register() failed for %s, error: %d\n",
+                        drv->driver.name, error);
+                return error;
+        }
+
+        /*
+         * Restore original bind mode and let kseriod bind the
+         * driver to free ports
+         */
+        if (!manual_bind) {
+                drv->manual_bind = 0;
+                error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
+                if (error) {
+                        driver_unregister(&drv->driver);
+                        return error;
+                }
+        }
+
+        return 0;
 }
 
 void serio_unregister_driver(struct serio_driver *drv)
diff --git a/include/linux/serio.h b/include/linux/serio.h
index 8f52228390ab..0f478a8791a2 100644
--- a/include/linux/serio.h
+++ b/include/linux/serio.h
@@ -86,12 +86,7 @@ static inline void serio_register_port(struct serio *serio)
 void serio_unregister_port(struct serio *serio);
 void serio_unregister_child_port(struct serio *serio);
 
-void __serio_register_driver(struct serio_driver *drv, struct module *owner);
-static inline void serio_register_driver(struct serio_driver *drv)
-{
-        __serio_register_driver(drv, THIS_MODULE);
-}
-
+int serio_register_driver(struct serio_driver *drv);
 void serio_unregister_driver(struct serio_driver *drv);
 
 static inline int serio_write(struct serio *serio, unsigned char data)