diff options
author | Johan Hovold <johan@kernel.org> | 2019-11-05 13:36:36 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-07 13:16:48 +0300 |
commit | 79c36a704a87533ba1551170354f3fb507ff5b70 (patch) | |
tree | 36ac4163edf4d46010f4a0880828d4f58974aa43 | |
parent | e76b3bf7654c3c94554c24ba15a3d105f4006c80 (diff) | |
download | linux-79c36a704a87533ba1551170354f3fb507ff5b70.tar.xz |
USB: idmouse: simplify disconnect handling
Since commit d4ead16f50f9 ("USB: prevent char device open/deregister
race") core prevents further calls to open() after usb_deregister_dev()
returns so there's no need to use the interface data for
synchronisation.
This effectively reverts commit 54d2bc068fd2 ("USB: fix locking in
idmouse") with respect to the open-disconnect race.
Note that the driver already uses a present flag to suppress I/O post
disconnect (even if all USB I/O take place at open).
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191105103638.4929-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/usb/misc/idmouse.c | 20 |
1 files changed, 2 insertions, 18 deletions
diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c index 20b0f91a5d9b..0386bac224c4 100644 --- a/drivers/usb/misc/idmouse.c +++ b/drivers/usb/misc/idmouse.c @@ -60,7 +60,6 @@ static const struct usb_device_id idmouse_table[] = { USB_TYPE_VENDOR | USB_RECIP_ENDPOINT | USB_DIR_OUT, value, index, NULL, 0, 1000) MODULE_DEVICE_TABLE(usb, idmouse_table); -static DEFINE_MUTEX(open_disc_mutex); /* structure to hold all of our device specific stuff */ struct usb_idmouse { @@ -227,17 +226,13 @@ static int idmouse_open(struct inode *inode, struct file *file) if (!interface) return -ENODEV; - mutex_lock(&open_disc_mutex); /* get the device information block from the interface */ dev = usb_get_intfdata(interface); - if (!dev) { - mutex_unlock(&open_disc_mutex); + if (!dev) return -ENODEV; - } /* lock this device */ mutex_lock(&dev->lock); - mutex_unlock(&open_disc_mutex); /* check if already open */ if (dev->open) { @@ -280,14 +275,12 @@ static int idmouse_release(struct inode *inode, struct file *file) if (dev == NULL) return -ENODEV; - mutex_lock(&open_disc_mutex); /* lock our device */ mutex_lock(&dev->lock); /* are we really open? */ if (dev->open <= 0) { mutex_unlock(&dev->lock); - mutex_unlock(&open_disc_mutex); return -ENODEV; } @@ -296,11 +289,9 @@ static int idmouse_release(struct inode *inode, struct file *file) if (!dev->present) { /* the device was unplugged before the file was released */ mutex_unlock(&dev->lock); - mutex_unlock(&open_disc_mutex); idmouse_delete(dev); } else { mutex_unlock(&dev->lock); - mutex_unlock(&open_disc_mutex); } return 0; } @@ -379,7 +370,6 @@ static int idmouse_probe(struct usb_interface *interface, if (result) { /* something prevented us from registering this device */ dev_err(&interface->dev, "Unable to allocate minor number.\n"); - usb_set_intfdata(interface, NULL); idmouse_delete(dev); return result; } @@ -392,19 +382,13 @@ static int idmouse_probe(struct usb_interface *interface, static void idmouse_disconnect(struct usb_interface *interface) { - struct usb_idmouse *dev; - - /* get device structure */ - dev = usb_get_intfdata(interface); + struct usb_idmouse *dev = usb_get_intfdata(interface); /* give back our minor */ usb_deregister_dev(interface, &idmouse_class); - mutex_lock(&open_disc_mutex); - usb_set_intfdata(interface, NULL); /* lock the device */ mutex_lock(&dev->lock); - mutex_unlock(&open_disc_mutex); /* prevent device read, write and ioctl */ dev->present = 0; |