Re: pcmcia's use of IRQ_NOAUTOEN

From: Alan Cox
Date: Mon Mar 15 2010 - 14:08:17 EST


On Mon, 8 Mar 2010 20:47:57 +0100
Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> wrote:

> Hey,
>
> On Mon, Mar 08, 2010 at 10:17:11AM +0000, Jan Beulich wrote:
> > (re-sending to correct Alan's email address)
> >
> > Commit 635416ef393e8cec5a89fc6c1de710ee9596a51e introduced
> > this, but I can't see how it can take effect - the argument passed
> > to request_irq() only affects action->flags (IRQF_*), whereas the
> > flag in question is a desc->status one (IRQ_*). Am I overlooking
> > something? If not, while currently this just should not work as
> > expected, it's latently more significant (as soon as the IRQF_*
> > definitions make use of the bit used by IRQ_NOAUTOEN).
>
> You're right, it seems to make no sense. Or less than that.
>
> Alan, what do you think?

It should be setting the correct NOAUTOEN bits so that the IRQ isn't
randomly enabled as some hardware then crashes. How it ended up wrong
upstream I don't know as it was tested and fixed the bug, so presumably
the right version got tested or it happened to work back on the old irq
code by luck.

I don't think you are overlooking anything - there is no deep magic
involved.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/