usb_lock_device_for_(9)
NAME
usb_lock_device_for_reset - cautiously acquire the lock for a usb
device structure
SYNOPSIS
int usb_lock_device_for_reset(struct usb_device * udev,
const struct usb_interface * iface);
ARGUMENTS
- udev
- device thatīs being locked
- iface
- interface bound to the driver making the request (optional)
DESCRIPTION
Attempts to acquire the device lock, but fails if the device is
NOTATTACHED or SUSPENDED, or if iface is specified and the interface is
neither BINDING nor BOUND. Rather than sleeping to wait for the lock,
the routine polls repeatedly. This is to prevent deadlock with
disconnect; in some drivers (such as usb-storage) the disconnect or
suspend method will block waiting for a device reset to complete.
Returns a negative error code for failure, otherwise 1 or 0 to indicate
that the device will or will not have to be unlocked. (0 can be
returned when an interface is given and is BINDING, because in that
case the driver already owns the device lock.)