diff options
Diffstat (limited to 'drivers/usb/misc/idmouse.c')
-rw-r--r-- | drivers/usb/misc/idmouse.c | 54 |
1 files changed, 15 insertions, 39 deletions
diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c index 8d0e360636e6..e6fd024024f5 100644 --- a/drivers/usb/misc/idmouse.c +++ b/drivers/usb/misc/idmouse.c @@ -119,9 +119,6 @@ static struct usb_driver idmouse_driver = { .id_table = idmouse_table, }; -/* prevent races between open() and disconnect() */ -static DEFINE_MUTEX(disconnect_mutex); - static int idmouse_create_image(struct usb_idmouse *dev) { int bytes_read; @@ -211,21 +208,15 @@ static int idmouse_open(struct inode *inode, struct file *file) struct usb_interface *interface; int result; - /* prevent disconnects */ - mutex_lock(&disconnect_mutex); - /* get the interface from minor number and driver information */ interface = usb_find_interface (&idmouse_driver, iminor (inode)); - if (!interface) { - mutex_unlock(&disconnect_mutex); + if (!interface) return -ENODEV; - } + /* get the device information block from the interface */ dev = usb_get_intfdata(interface); - if (!dev) { - mutex_unlock(&disconnect_mutex); + if (!dev) return -ENODEV; - } /* lock this device */ down(&dev->sem); @@ -255,9 +246,6 @@ error: /* unlock this device */ up(&dev->sem); - - /* unlock the disconnect semaphore */ - mutex_unlock(&disconnect_mutex); return result; } @@ -265,15 +253,10 @@ static int idmouse_release(struct inode *inode, struct file *file) { struct usb_idmouse *dev; - /* prevent a race condition with open() */ - mutex_lock(&disconnect_mutex); - dev = file->private_data; - if (dev == NULL) { - mutex_unlock(&disconnect_mutex); + if (dev == NULL) return -ENODEV; - } /* lock our device */ down(&dev->sem); @@ -281,7 +264,6 @@ static int idmouse_release(struct inode *inode, struct file *file) /* are we really open? */ if (dev->open <= 0) { up(&dev->sem); - mutex_unlock(&disconnect_mutex); return -ENODEV; } @@ -291,12 +273,9 @@ static int idmouse_release(struct inode *inode, struct file *file) /* the device was unplugged before the file was released */ up(&dev->sem); idmouse_delete(dev); - mutex_unlock(&disconnect_mutex); - return 0; + } else { + up(&dev->sem); } - - up(&dev->sem); - mutex_unlock(&disconnect_mutex); return 0; } @@ -391,30 +370,27 @@ static void idmouse_disconnect(struct usb_interface *interface) { struct usb_idmouse *dev; - /* prevent races with open() */ - mutex_lock(&disconnect_mutex); - /* get device structure */ dev = usb_get_intfdata(interface); usb_set_intfdata(interface, NULL); - /* lock it */ - down(&dev->sem); - /* give back our minor */ usb_deregister_dev(interface, &idmouse_class); + /* lock it */ + down(&dev->sem); + /* prevent device read, write and ioctl */ dev->present = 0; - /* unlock */ - up(&dev->sem); - /* if the device is opened, idmouse_release will clean this up */ - if (!dev->open) + if (!dev->open) { + up(&dev->sem); idmouse_delete(dev); - - mutex_unlock(&disconnect_mutex); + } else { + /* unlock */ + up(&dev->sem); + } info("%s disconnected", DRIVER_DESC); } |