PARPORT_YIELD(9) Parallel Port Devices PARPORT_YIELD(9)NAMEparport_yield - relinquish a parallel port temporarily
SYNOPSIS
int parport_yield(struct pardevice * dev);
ARGUMENTS
dev
a device on the parallel port
DESCRIPTION
This function relinquishes the port if it would be helpful to other
drivers to do so. Afterwards it tries to reclaim the port using
parport_claim, and the return value is the same as for parport_claim.
If it fails, the port is left unclaimed and it is the driver´s
responsibility to reclaim the port.
The parport_yield and parport_yield_blocking functions are for marking
points in the driver at which other drivers may claim the port and use
their devices. Yielding the port is similar to releasing it and
reclaiming it, but is more efficient because no action is taken if
there are no other devices needing the port. In fact, nothing is done
even if there are other devices waiting but the current device is still
within its “timeslice”. The default timeslice is half a second, but it
can be adjusted via the /proc interface.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 PARPORT_YIELD(9)