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 <[email protected]> --- drivers/usb/misc/iowarrior.c | 17 ++--------------- 1 file 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 @@ static int iowarrior_probe(struct usb_interface *interface, */ 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); -- 2.23.0
