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Commit ab7cd8c7 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Revert "USB: Close usb_find_interface race"



This reverts commit a2582bd4.

It turned out to be buggy and broke USB printers from working.

Cc: Russ Dill <Russ.Dill@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3ea6b3d0
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+18 −10
Original line number Diff line number Diff line
@@ -167,17 +167,24 @@ struct usb_host_interface *usb_altnum_to_altsetting(
}
EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);

struct find_interface_arg {
	int minor;
	struct usb_interface *interface;
};

static int __find_interface(struct device *dev, void *data)
{
	int *minor = data;
	struct find_interface_arg *arg = data;
	struct usb_interface *intf;

	if (!is_usb_interface(dev))
		return 0;

	intf = to_usb_interface(dev);
	if (intf->minor != -1 && intf->minor == *minor)
	if (intf->minor != -1 && intf->minor == arg->minor) {
		arg->interface = intf;
		return 1;
	}
	return 0;
}

@@ -186,20 +193,21 @@ static int __find_interface(struct device *dev, void *data)
 * @drv: the driver whose current configuration is considered
 * @minor: the minor number of the desired device
 *
 * This walks the bus device list and returns a pointer to the interface
 * This walks the driver device list and returns a pointer to the interface
 * with the matching minor.  Note, this only works for devices that share the
 * USB major number.
 */
struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
{
	struct device *dev;

	dev = bus_find_device(&usb_bus_type, NULL, &minor, __find_interface);

	/* Drop reference count from bus_find_device */
	put_device(dev);
	struct find_interface_arg argb;
	int retval;

	return dev ? to_usb_interface(dev) : NULL;
	argb.minor = minor;
	argb.interface = NULL;
	/* eat the error, it will be in argb.interface */
	retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
					__find_interface);
	return argb.interface;
}
EXPORT_SYMBOL_GPL(usb_find_interface);