forked from luck/tmp_suning_uos_patched
USB: kill BKL in skeleton driver
Iet's kill BKL where we can. This is relative to the last patch to the skeleton driver. Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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@ -34,6 +34,9 @@ static struct usb_device_id skel_table [] = {
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};
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MODULE_DEVICE_TABLE(usb, skel_table);
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/* to prevent a race between open and disconnect */
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static DEFINE_MUTEX(skel_open_lock);
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/* Get a minor range for your devices from the usb maintainer */
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#define USB_SKEL_MINOR_BASE 192
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@ -80,8 +83,10 @@ static int skel_open(struct inode *inode, struct file *file)
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subminor = iminor(inode);
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mutex_lock(&skel_open_lock);
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interface = usb_find_interface(&skel_driver, subminor);
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if (!interface) {
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mutex_unlock(&skel_open_lock);
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err ("%s - error, can't find device for minor %d",
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__FUNCTION__, subminor);
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retval = -ENODEV;
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@ -90,12 +95,15 @@ static int skel_open(struct inode *inode, struct file *file)
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dev = usb_get_intfdata(interface);
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if (!dev) {
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mutex_unlock(&skel_open_lock);
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retval = -ENODEV;
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goto exit;
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}
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/* increment our usage count for the device */
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kref_get(&dev->kref);
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/* now we can drop the lock */
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mutex_unlock(&skel_open_lock);
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/* prevent the device from being autosuspended */
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retval = usb_autopm_get_interface(interface);
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@ -361,14 +369,14 @@ static void skel_disconnect(struct usb_interface *interface)
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int minor = interface->minor;
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/* prevent skel_open() from racing skel_disconnect() */
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lock_kernel();
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mutex_lock(&skel_open_lock);
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dev = usb_get_intfdata(interface);
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usb_set_intfdata(interface, NULL);
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/* give back our minor */
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usb_deregister_dev(interface, &skel_class);
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unlock_kernel();
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mutex_unlock(&skel_open_lock);
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/* prevent more I/O from starting */
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mutex_lock(&dev->io_mutex);
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