summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJohan Hovold <johan@kernel.org>2019-10-09 13:48:44 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-10 13:45:06 +0300
commit7c5b971d623fdb40c03205e99f9ef68002b34726 (patch)
treecf70ffb402c783466d0a1dfb96409e8e887bca77
parentb5f8d46867ca233d773408ffbe691a8062ed718f (diff)
downloadlinux-7c5b971d623fdb40c03205e99f9ef68002b34726.tar.xz
USB: iowarrior: drop redundant disconnect mutex
Drop the redundant disconnect mutex which was introduced after the open-disconnect race had been addressed generally in USB core by commit d4ead16f50f9 ("USB: prevent char device open/deregister race"). Specifically, the rw-semaphore in core guarantees that all calls to open() will have completed and that no new calls to open() will occur after usb_deregister_dev() returns. Hence there is no need use the driver data as an inverted disconnected flag. Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20191009104846.5925-5-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/misc/iowarrior.c17
1 files changed, 2 insertions, 15 deletions
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index f405fa734bcc..d844c2098e42 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -58,7 +58,6 @@ MODULE_LICENSE("GPL");
static DEFINE_MUTEX(iowarrior_mutex);
static struct usb_driver iowarrior_driver;
-static DEFINE_MUTEX(iowarrior_open_disc_lock);
/*--------------*/
/* data */
@@ -601,16 +600,13 @@ static int iowarrior_open(struct inode *inode, struct file *file)
return -ENODEV;
}
- mutex_lock(&iowarrior_open_disc_lock);
dev = usb_get_intfdata(interface);
if (!dev) {
- mutex_unlock(&iowarrior_open_disc_lock);
mutex_unlock(&iowarrior_mutex);
return -ENODEV;
}
mutex_lock(&dev->mutex);
- mutex_unlock(&iowarrior_open_disc_lock);
/* Only one process can open each device, no sharing. */
if (dev->opened) {
@@ -842,7 +838,6 @@ static int iowarrior_probe(struct usb_interface *interface,
if (retval) {
/* something prevented us from registering this driver */
dev_err(&interface->dev, "Not able to get a minor for this device.\n");
- usb_set_intfdata(interface, NULL);
goto error;
}
@@ -866,16 +861,8 @@ error:
*/
static void iowarrior_disconnect(struct usb_interface *interface)
{
- struct iowarrior *dev;
- int minor;
-
- dev = usb_get_intfdata(interface);
- mutex_lock(&iowarrior_open_disc_lock);
- usb_set_intfdata(interface, NULL);
-
- minor = dev->minor;
- mutex_unlock(&iowarrior_open_disc_lock);
- /* give back our minor - this will call close() locks need to be dropped at this point*/
+ struct iowarrior *dev = usb_get_intfdata(interface);
+ int minor = dev->minor;
usb_deregister_dev(interface, &iowarrior_class);