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

drivers/usb/core/usb.c

+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);