* Andrew Morton <a...@linux-foundation.org> wrote:
> On Fri, 27 Feb 2015 13:32:55 +0100 Valentin Rothberg
> <valentin.rothb...@lip6.fr> wrote:
>
> > The IRQF_DISABLED is a NOOP and scheduled to be removed. According to
> > Ingo Molnar (e58aa3d2d0cc01ad8d6f7f640a0670433f794922) running IRQ
> > handlers with interrupts enabled can cause stack overflows when the
> > interrupt line of the issuing device is still active.
> >
>
> I suggest you prepare a patch which removes IRQF_DISABLED entirely.
Yes.
> Several drivers still use it and it is possible that they have been
> buggy for some time, [...]
Well, IRQF_DISABLED is now the unconditional default, so requesting
irqs with IRQF_DISABLED is simply superfluous, not buggy, AFAICS.
> [...] so we should be careful to cc the relevant maintainers (they
> probably don't exist) so they can check out what's going on in their
> code.
I think part of it might be the stale spinlock related comment in
Documentation/PCI/MSI-HOWTO.txt which explicitly recommends
IRQF_DISABLED use. So that reference should be zapped as well.
So maybe drivers still using IRQF_DISABLED might not be potentially
broken drivers at all, but are drivers written by exceptionally
capable driver authors, who read kernel documentation!
Thanks,
Ingo
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