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path: root/drivers/usb/misc/idmouse.c
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Diffstat (limited to 'drivers/usb/misc/idmouse.c')
-rw-r--r--drivers/usb/misc/idmouse.c54
1 files changed, 15 insertions, 39 deletions
diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index 8d0e360636e..e6fd024024f 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);
}