Re: Linux 2.6.17: IRQ handler mismatch in serial code?

Bodo Eggert
2006-06-20T23:20:25Z

On Tue, 20 Jun 2006, Russell King wrote:
> On Tue, Jun 20, 2006 at 04:39:49PM +0200, Bodo Eggert wrote:

> > There are thousands of NE2K-clones, the driver can't know if sharing the IRQ
> > will be OK for a given card. Is the change for sharing IRQs trivial enough
> > to allow an if/else based on a load-time module parameter?
>
> Not if it's an ISA card. You need to loop over all interrupt source
> devices until you're certain that they have released the interrupt
> line before returning, otherwise you will end up with the IRQ line
> stuck in a state where it can't cause any further interrupts.
>
> The kernel has no such infrastructure, except within the serial driver
> to allow multiple serial ports to share a common interrupt.

What a pity - I hoped for a grab_shared_irq() which would do what you
describe.

--
Is reading in the bathroom considered Multitasking?