Re: revert yenta free_irq on suspend

[Andrew Morton <akpm@osdl.org>]

Shaohua Li <shaohua.li@intel.com> wrote:
>
> Hi,
> > In general, I think that calling free_irq is the right behavior.
> > Although irqs changing after suspend is rare, there are also some
> > more serious issues.  This has been discussed in the past, and a
> > summary is as follows:
>
> irqs actually isn't changed after suspend currently, it's a considering
> for future usage like hotplug.
> Calling free_irq actually isn't a complete ACPI issue, but ACPI requires
> it to solve nasty 'sleep in atomic' warning.

Is that the only problem?  If so, then surely we can make free_irq() run
happily with interrupts disabled: unlink the IRQ handler synchronously,
defer the /proc teardown or something like that.

> You will find such break
> with swsusp without ACPI. Could we revert the ACPI change in Linus's
> tree but keep it in -mm tree? So we get a chance to fix drivers.

That depends on the amount of brokenness involved: if it's significant then
I'll get a ton of bug reports concerning something which we already know is
broken and we'll drive away our long-suffering testers.