Re: [PARPORT] lp

Tim Waugh (
Wed, 1 Apr 1998 19:15:21 +0100 (BST)

On Wed, 1 Apr 1998, Andrea Arcangeli wrote:

> If the parport lowlevel driver will autodetect the right irq I don' t see
> how can it cause an harm.

People who had their Ethernet cards set up to IRQ 5 in 2.0.x might find
that suddenly it doesn't work in newer kernels. That's because parport
has (correctly) autodetected 5 as belonging to the parallel port, and
grabbed it for some other device driver.

> I don' t see the problem how lp specific but instead as parport_lowlevel
> specific. If lp will cause an harm every other pardevice that will use
> interrupt on the same parport will do the same.

That's true, but lp is currently the only device driver (that I know of)
that _uses_ interrupts if they have been autodetected by parport.
A better solution then might be to have to explicitly ask parport
to autoprobe for IRQs if you want interrupt-driven operation.

I guess the problem is that some device drivers _need_ interrupts, while
others find them helpful but not essential, and there's currently no way
to sort them all out properly.


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This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 10:17:34 EST