PARPORT_WAIT_PERIPHE(9)               Parallel Port Devices               PARPORT_WAIT_PERIPHE(9)



NAME
       parport_wait_peripheral - wait for status lines to change in 35ms

SYNOPSIS
       int parport_wait_peripheral(struct parport * port, unsigned char mask,
                                   unsigned char result);

ARGUMENTS
       port
           port to watch

       mask
           status lines to watch

       result
           desired values of chosen status lines

DESCRIPTION
       This function waits until the masked status lines have the desired values, or until 35ms
       have elapsed (see IEEE 1284-1994 page 24 to 25 for why this value in particular is
       hardcoded). The mask and result parameters are bitmasks, with the bits defined by the
       constants in parport.h: PARPORT_STATUS_BUSY, and so on.

       The port is polled quickly to start off with, in anticipation of a fast response from the
       peripheral. This fast polling time is configurable (using /proc), and defaults to 500usec.
       If the timeout for this port (see parport_set_timeout) is zero, the fast polling time is
       35ms, and this function does not call schedule.

       If the timeout for this port is non-zero, after the fast polling fails it uses
       parport_wait_event to wait for up to 10ms, waking up if an interrupt occurs.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   PARPORT_WAIT_PERIPHE(9)