Re: [GIT PATCH] more Driver core patches for 2.6.19

From: Greg KH
Date: Wed Dec 13 2006 - 15:31:54 EST


On Wed, Dec 13, 2006 at 12:12:04PM -0800, Linus Torvalds wrote:
>
>
> On Wed, 13 Dec 2006, Greg KH wrote:
> >
> > - userspace io driver interface added. This allows the ability
> > to write userspace drivers for some types of hardware much
> > easier than before, going through a simple interface to get
> > accesses to irqs and memory regions. A small kernel portion
> > is still needed to handle the irq properly, but that is it.
>
> Ok, what kind of ass-hat idiotic thing is this?
>
> irqreturn_t uio_irq_handler(int irq, void *dev_id)
> {
> return IRQ_HANDLED;
> }
>
> exactly what is the point here? No way will I pull this kind of crap. You
> just seem to have guaranteed a dead machine if the irq is level-triggered,
> since it will keep on happening forever.

It's a stupid test module for the uio core for isa devices. It's not
the main code, or core.

> Please remove.
>
> YOU CANNOT DO IRQ'S BY LETTING USER SPACE SORT IT OUT!

I agree, that's why this code doesn't let userspace sort it out. You
have to have a kernel driver to handle the irq.

> It's really that easy. The irq handler has to be _entirely_ in kernel
> space. No user-space ass-hattery here.

Agreed.

> And I don't care one whit if it happens to work on parport with an old
> legacy ISA interrupt that is edge-triggered. That's not even the
> interesting case. Never will be.

I agree. But that's all that this test module did. It handled an isa
interrupt that was edge triggered.

> NAK NAK NAK NAK.

Ok, I can pull this example module out if you want, but people seem to
want examples these days. If I do that, any objection to the rest?

thanks,

greg k-h
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