diff options
| -rw-r--r-- | drivers/usb/core/file.c | 70 |
1 files changed, 54 insertions, 16 deletions
diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c index 70898716dd9..f65b193cde3 100644 --- a/drivers/usb/core/file.c +++ b/drivers/usb/core/file.c @@ -61,33 +61,66 @@ static struct file_operations usb_fops = { .open = usb_open, }; -static struct class *usb_class; +static struct usb_class { + struct kref kref; + struct class *class; +} *usb_class; -int usb_major_init(void) +static int init_usb_class(void) { - int error; + int result = 0; - error = register_chrdev(USB_MAJOR, "usb", &usb_fops); - if (error) { - err("unable to get major %d for usb devices", USB_MAJOR); - goto out; + if (usb_class != NULL) { + kref_get(&usb_class->kref); + goto exit; + } + + usb_class = kmalloc(sizeof(*usb_class), GFP_KERNEL); + if (!usb_class) { + result = -ENOMEM; + goto exit; } - usb_class = class_create(THIS_MODULE, "usb"); - if (IS_ERR(usb_class)) { - error = PTR_ERR(usb_class); + kref_init(&usb_class->kref); + usb_class->class = class_create(THIS_MODULE, "usb"); + if (IS_ERR(usb_class->class)) { + result = IS_ERR(usb_class->class); err("class_create failed for usb devices"); - unregister_chrdev(USB_MAJOR, "usb"); - goto out; + kfree(usb_class); + usb_class = NULL; } -out: +exit: + return result; +} + +static void release_usb_class(struct kref *kref) +{ + /* Ok, we cheat as we know we only have one usb_class */ + class_destroy(usb_class->class); + kfree(usb_class); + usb_class = NULL; +} + +static void destroy_usb_class(void) +{ + if (usb_class) + kref_put(&usb_class->kref, release_usb_class); +} + +int usb_major_init(void) +{ + int error; + + error = register_chrdev(USB_MAJOR, "usb", &usb_fops); + if (error) + err("unable to get major %d for usb devices", USB_MAJOR); + return error; } void usb_major_cleanup(void) { - class_destroy(usb_class); unregister_chrdev(USB_MAJOR, "usb"); } @@ -149,6 +182,10 @@ int usb_register_dev(struct usb_interface *intf, if (retval) goto exit; + retval = init_usb_class(); + if (retval) + goto exit; + intf->minor = minor; /* create a usb class device for this usb interface */ @@ -158,7 +195,7 @@ int usb_register_dev(struct usb_interface *intf, ++temp; else temp = name; - intf->usb_dev = device_create(usb_class, &intf->dev, + intf->usb_dev = device_create(usb_class->class, &intf->dev, MKDEV(USB_MAJOR, minor), "%s", temp); if (IS_ERR(intf->usb_dev)) { spin_lock (&minor_lock); @@ -205,9 +242,10 @@ void usb_deregister_dev(struct usb_interface *intf, spin_unlock (&minor_lock); snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base); - device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor)); + device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor)); intf->usb_dev = NULL; intf->minor = -1; + destroy_usb_class(); } EXPORT_SYMBOL(usb_deregister_dev); |