Re: lockdep and threaded IRQs (was: ...)

Ingo Molnar
2009-03-03T10:04:17Z

* Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

> > Therefore IRQF_DISABLED _will_ be forced on everybody some
> > day soon, and I'll provide an IRQF_ENABLED for use by broken
> > hardware only (and make a TAINT flag for that too).
>
> I don't think you understand how the kernel project works. If
> everyone thinks your change is inappropriate it won't get in.

The change that people had a problem with was the immediate
removal of IRQF_ENABLED, and that's not on the plate anymore.

I dont think anyone offered any example where IRQF_ENABLED is
used in a healthy way - they are all legacy or special hw quirks
where we limp along with enabling IRQs in a hacky way.

Furthermore, even these quirky cases can be supported cleanly
_without_ IRQF_ENABLED: where an IRQ handler can take a long
time to execute, the handler can be converted to a threaded IRQ
handler - where it's fine to enable IRQs as there are no stack
nesting issues.

So there's no real technical problem here.

Ingo