usb_autopm_get_interface — increment a USB interface's PM-usage counter
int usb_autopm_get_interface ( | struct usb_interface * intf); |
This routine should be called by an interface driver when it wants to
use intf and needs to guarantee that it is not suspended. In addition,
the routine prevents intf from being autosuspended subsequently. (Note
that this will not prevent suspend events originating in the PM core.)
This prevention will persist until usb_autopm_put_interface is called
or intf is unbound. A typical example would be a character-device
driver when its device file is opened.
intf's usage counter is incremented to prevent subsequent autosuspends.
However if the autoresume fails then the counter is re-decremented.
This routine can run only in process context.