Parallel Printing

Matthew Dillon dillon at apollo.backplane.com
Thu Oct 28 01:20:28 PDT 2004


:Hi,
:   When printing with a parallel printer I get a lot of messages on the
:   console like,
:
:   intr 7 at 55539 hz, livelocked ! limiting at 20000 hz
:   intr 7 at 9959 hz, removing livelock limit.
:
:   Switching to polled mode with lptcontrol(8) fixes this but I am
:   wondering whether I should try,
:
:   options DEVICE_POLLING
:
:   in my kernel. I do have a dc0 ( AMDTek Comet ) NIC which is supposed
:   to support this but reading LINT gives the impression that this is a
:   work in progress.
:
:   At the moment I am lucky enough that the GENERIC kernel supports all
:   my hardware. I do have to disable acpi to get the floppy drive
:   recognised though.
:
:   Just updated STABLE but this made no difference to any of this. Very
:   smooth update though, thank you !
:
:                             Thanks for any help,
:                                  John Duncan

    Do whatever works.  You could just try bumping up the livelock 
    frequency trip points which are the kern.livelock_limit and
    kern.livelock_fallback sysctls.

    I would have thought that the parallel port's FIFO would be enough to
    reduce the interrupt rate to reasonable levels but I guess not.  polling
    is certainly one solution.  If the transfer rate isn't too slow for you
    that would be my first choice.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





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