Re: Parallel Printing

[Joerg Sonnenberger <joerg@xxxxxxxxxxxxxxxxx>]

On Thu, Oct 28, 2004 at 08:53:26AM +1000, John Duncan wrote:
>    intr 7 at 55539 hz, livelocked ! limiting at 20000 hz
>    intr 7 at 9959 hz, removing livelock limit.

This indicates an interrupt storm for interrupt 7. If this actually is
your parport, it might well be normal to generate an interrupt per package
:)

>    Switching to polled mode with lptcontrol(8) fixes this but I am
>    wondering whether I should try,

Polled mode via lptcontrol helps by avoiding the interrupt overhead and
replacing it with explicit checks. You should first check if any devices
share share interrupt 7, that could be one source of the livelock.

> 
>    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.

This doesn't really help you with your problem if dc0 doesn't use irq 7.
If it does, yes, this can solve it.

Joerg