Re: [PATCH 12/17] ARM: OMAP2+: remove misuse of IRQF_NO_SUSPEND flag

[Sudeep Holla]

On 13/10/15 15:53, Tony Lindgren wrote:
> * Sudeep Holla <sudeep.holla@xxxxxxx> [151013 03:46]:
> > On 12/10/15 21:28, Tony Lindgren wrote:
> > > * Tony Lindgren <tony@xxxxxxxxxxx> [151012 13:27]:
> > > > * Sudeep Holla <sudeep.holla@xxxxxxx> [150921 08:52]:
> > > > > The IRQF_NO_SUSPEND flag is used to identify the interrupts that should
> > > > > be left enabled so as to allow them to work as expected during the
> > > > > suspend-resume cycle, but doesn't guarantee that it will wake the system
> > > > >from a suspended state, enable_irq_wake is recommended to be used for
> > > > > the wakeup.
> > > > >
> > > > > This patch removes the use of IRQF_NO_SUSPEND flags replacing it with
> > > > > enable_irq_wake instead.
> > > >
> > > > Applying into omap-for-v4.4/cleanup thanks.
> > >
> > > Actually I don't think this does the right thing. The interrupts
> > > in the $subject patch are in the always on powerdomain, and we really
> >
> > Agreed
> >
> > > want them to be excluded from the suspend.
> >
> > OK but what's wrong with this patch. At-least the name suggest it's a
> > wakeup interrupt. And using IRQF_NO_SUSPEND for the wakeup interrupt is
> > simply wrong.
>
> Hmm so if we have a separate always on irq controller for the wake-up events
> and we want to keep it always on and exclude it from any suspend related
> things.. Why would we not use IRQF_NO_SUSPEND on it?
>
> Above you say "The IRQF_NO_SUSPEND flag is used to identify the interrupts
> that should be left enabled so as to allow them to work as expected during
> the suspend-resume cycle..." and that's exactly what we want to do here :)

OK if these interrupts meet that criteria to use IRQF_NO_SUSPEND, then
it should be fine, my earlier argument was based on the assumption that
it's just another wakeup interrupt.

> For the dedicated wake-up interrupts, we have separate registers to enable
> and disable them. The $subject irq is the shared interrupt that allows
> making use of the pin specific wake-up interrupts, and for those yes we
> are using enable_irq_wake().

If it's already take care, then fine. I am just hunting all the misuse
of IRQF_NO_SUSPEND flag especially as wakeup source and fixing them

> > > So not applying without further explanations.
> >
> > But I don't understand the real need for IRQF_NO_SUSPEND over wakeup APIs ?
>
> Because in the $subject case we just want to always keep it on and
> never suspend it. It's unrelated to the wakeup APIs at least for the
> omap related SoCs.

OK, understood now. Thanks

--
Regards,
Sudeep
--
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/