Input: gameport - make gameport_register_driver() return errors

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

Note that driver <-> port matching is still done by kgameportd.

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

2 files changed, 71 insertions, 24 deletions

diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index 078e4eed089..2880eaae157 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -231,6 +231,7 @@ static void gameport_find_driver(struct gameport *gameport)
 enum gameport_event_type {
         GAMEPORT_REGISTER_PORT,
         GAMEPORT_REGISTER_DRIVER,
+        GAMEPORT_ATTACH_DRIVER,
 };
 
 struct gameport_event {
@@ -245,11 +246,12 @@ static LIST_HEAD(gameport_event_list);
 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait);
 static struct task_struct *gameport_task;
 
-static void gameport_queue_event(void *object, struct module *owner,
-                              enum gameport_event_type event_type)
+static int gameport_queue_event(void *object, struct module *owner,
+                                enum gameport_event_type event_type)
 {
         unsigned long flags;
         struct gameport_event *event;
+        int retval = 0;
 
         spin_lock_irqsave(&gameport_event_lock, flags);
 
@@ -268,24 +270,34 @@ static void gameport_queue_event(void *object, struct module *owner,
                 }
         }
 
-        if ((event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC))) {
-                if (!try_module_get(owner)) {
-                        printk(KERN_WARNING "gameport: 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 gameport_event), GFP_ATOMIC);
+        if (!event) {
+                printk(KERN_ERR
+                        "gameport: Not enough memory to queue event %d\n",
+                        event_type);
+                retval = -ENOMEM;
+                goto out;
+        }
 
-                list_add_tail(&event->node, &gameport_event_list);
-                wake_up(&gameport_wait);
-        } else {
-                printk(KERN_ERR "gameport: Not enough memory to queue event %d\n", event_type);
+        if (!try_module_get(owner)) {
+                printk(KERN_WARNING
+                        "gameport: 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, &gameport_event_list);
+        wake_up(&gameport_wait);
+
 out:
         spin_unlock_irqrestore(&gameport_event_lock, flags);
+        return retval;
 }
 
 static void gameport_free_event(struct gameport_event *event)
@@ -378,9 +390,10 @@ static void gameport_handle_event(void)
 }
 
 /*
- * Remove all events that have been submitted for a given gameport port.
+ * Remove all events that have been submitted for a given object,
+ * be it a gameport port or a driver.
  */
-static void gameport_remove_pending_events(struct gameport *gameport)
+static void gameport_remove_pending_events(void *object)
 {
         struct list_head *node, *next;
         struct gameport_event *event;
@@ -390,7 +403,7 @@ static void gameport_remove_pending_events(struct gameport *gameport)
 
         list_for_each_safe(node, next, &gameport_event_list) {
                 event = list_entry(node, struct gameport_event, node);
-                if (event->object == gameport) {
+                if (event->object == object) {
                         list_del_init(node);
                         gameport_free_event(event);
                 }
@@ -705,10 +718,40 @@ static void gameport_add_driver(struct gameport_driver *drv)
                         drv->driver.name, error);
 }
 
-void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
+int __gameport_register_driver(struct gameport_driver *drv, struct module *owner,
+                                const char *mod_name)
 {
+        int error;
+
         drv->driver.bus = &gameport_bus;
-        gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
+        drv->driver.owner = owner;
+        drv->driver.mod_name = mod_name;
+
+        /*
+         * Temporarily disable automatic binding because probing
+         * takes long time and we are better off doing it in kgameportd
+         */
+        drv->ignore = 1;
+
+        error = driver_register(&drv->driver);
+        if (error) {
+                printk(KERN_ERR
+                        "gameport: driver_register() failed for %s, error: %d\n",
+                        drv->driver.name, error);
+                return error;
+        }
+
+        /*
+         * Reset ignore flag and let kgameportd bind the driver to free ports
+         */
+        drv->ignore = 0;
+        error = gameport_queue_event(drv, NULL, GAMEPORT_ATTACH_DRIVER);
+        if (error) {
+                driver_unregister(&drv->driver);
+                return error;
+        }
+
+        return 0;
 }
 
 void gameport_unregister_driver(struct gameport_driver *drv)
@@ -716,7 +759,9 @@ void gameport_unregister_driver(struct gameport_driver *drv)
         struct gameport *gameport;
 
         mutex_lock(&gameport_mutex);
+
         drv->ignore = 1;        /* so gameport_find_driver ignores it */
+        gameport_remove_pending_events(drv);
 
 start_over:
         list_for_each_entry(gameport, &gameport_list, node) {
@@ -729,6 +774,7 @@ start_over:
         }
 
         driver_unregister(&drv->driver);
+
         mutex_unlock(&gameport_mutex);
 }
 
diff --git a/include/linux/gameport.h b/include/linux/gameport.h
index f64e29c0ef3..5126125afd4 100644
--- a/include/linux/gameport.h
+++ b/include/linux/gameport.h
@@ -146,10 +146,11 @@ static inline void gameport_unpin_driver(struct gameport *gameport)
         mutex_unlock(&gameport->drv_mutex);
 }
 
-void __gameport_register_driver(struct gameport_driver *drv, struct module *owner);
-static inline void gameport_register_driver(struct gameport_driver *drv)
+int __gameport_register_driver(struct gameport_driver *drv,
+                                struct module *owner, const char *mod_name);
+static inline int gameport_register_driver(struct gameport_driver *drv)
 {
-        __gameport_register_driver(drv, THIS_MODULE);
+        return __gameport_register_driver(drv, THIS_MODULE, KBUILD_MODNAME);
 }
 
 void gameport_unregister_driver(struct gameport_driver *drv);