Input: make input_register_handler() return error codes

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

drivers/char/keyboard.c

@@ -1362,6 +1362,7 @@ static struct input_handler kbd_handler = {
 int __init kbd_init(void)
 {
 	int i;
+	int error;
 
         for (i = 0; i < MAX_NR_CONSOLES; i++) {
 		kbd_table[i].ledflagstate = KBD_DEFLEDS;
@@ -1373,7 +1374,9 @@ int __init kbd_init(void)
 		kbd_table[i].kbdmode = VC_XLATE;
 	}
 
-	input_register_handler(&kbd_handler);
+	error = input_register_handler(&kbd_handler);
+	if (error)
+		return error;
 
 	tasklet_enable(&keyboard_tasklet);
 	tasklet_schedule(&keyboard_tasklet);

drivers/input/evbug.c

@@ -91,8 +91,7 @@ static struct input_handler evbug_handler = {
 
 static int __init evbug_init(void)
 {
-	input_register_handler(&evbug_handler);
-	return 0;
+	return input_register_handler(&evbug_handler);
 }
 
 static void __exit evbug_exit(void)

drivers/input/evdev.c

@@ -695,8 +695,7 @@ static struct input_handler evdev_handler = {
 
 static int __init evdev_init(void)
 {
-	input_register_handler(&evdev_handler);
-	return 0;
+	return input_register_handler(&evdev_handler);
 }
 
 static void __exit evdev_exit(void)

drivers/input/input.c

@@ -1037,19 +1037,20 @@ void input_unregister_device(struct input_dev *dev)
 }
 EXPORT_SYMBOL(input_unregister_device);
 
-void input_register_handler(struct input_handler *handler)
+int input_register_handler(struct input_handler *handler)
 {
 	struct input_dev *dev;
 	struct input_handle *handle;
 	const struct input_device_id *id;
 
-	if (!handler)
-		return;
-
 	INIT_LIST_HEAD(&handler->h_list);
 
-	if (handler->fops != NULL)
+	if (handler->fops != NULL) {
+		if (input_table[handler->minor >> 5])
+			return -EBUSY;
+
 		input_table[handler->minor >> 5] = handler;
+	}
 
 	list_add_tail(&handler->node, &input_handler_list);
 
@@ -1063,6 +1064,7 @@ void input_register_handler(struct input_handler *handler)
 				}
 
 	input_wakeup_procfs_readers();
+	return 0;
 }
 EXPORT_SYMBOL(input_register_handler);
 

drivers/input/joydev.c

@@ -606,8 +606,7 @@ static struct input_handler joydev_handler = {
 
 static int __init joydev_init(void)
 {
-	input_register_handler(&joydev_handler);
-	return 0;
+	return input_register_handler(&joydev_handler);
 }
 
 static void __exit joydev_exit(void)

drivers/input/mousedev.c

@@ -738,7 +738,12 @@ static int psaux_registered;
 
 static int __init mousedev_init(void)
 {
-	input_register_handler(&mousedev_handler);
+	struct class_device *cdev;
+	int error;
+
+	error = input_register_handler(&mousedev_handler);
+	if (error)
+		return error;
 
 	memset(&mousedev_mix, 0, sizeof(struct mousedev));
 	INIT_LIST_HEAD(&mousedev_mix.list);
@@ -747,12 +752,20 @@ static int __init mousedev_init(void)
 	mousedev_mix.exist = 1;
 	mousedev_mix.minor = MOUSEDEV_MIX;
 
-	class_device_create(&input_class, NULL,
+	cdev = class_device_create(&input_class, NULL,
 			MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + MOUSEDEV_MIX), NULL, "mice");
+	if (IS_ERR(cdev)) {
+		input_unregister_handler(&mousedev_handler);
+		return PTR_ERR(cdev);
+	}
 
 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
-	if (!(psaux_registered = !misc_register(&psaux_mouse)))
-		printk(KERN_WARNING "mice: could not misc_register the device\n");
+	error = misc_register(&psaux_mouse);
+	if (error)
+		printk(KERN_WARNING "mice: could not register psaux device, "
+			"error: %d\n", error);
+	else
+		psaux_registered = 1;
 #endif
 
 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");

drivers/input/power.c

@@ -150,8 +150,7 @@ static struct input_handler power_handler = {
 
 static int __init power_init(void)
 {
-	input_register_handler(&power_handler);
-	return 0;
+	return input_register_handler(&power_handler);
 }
 
 static void __exit power_exit(void)

drivers/input/tsdev.c

@@ -479,9 +479,7 @@ static struct input_handler tsdev_handler = {
 
 static int __init tsdev_init(void)
 {
-	input_register_handler(&tsdev_handler);
-	printk(KERN_INFO "ts: Compaq touchscreen protocol output\n");
-	return 0;
+	return input_register_handler(&tsdev_handler);
 }
 
 static void __exit tsdev_exit(void)

include/linux/input.h

@@ -1106,7 +1106,7 @@ static inline void input_put_device(struct input_dev *dev)
 int input_register_device(struct input_dev *);
 void input_unregister_device(struct input_dev *);
 
-void input_register_handler(struct input_handler *);
+int input_register_handler(struct input_handler *);
 void input_unregister_handler(struct input_handler *);
 
 int input_grab_device(struct input_handle *);