[PATCH 04/17] powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of redundant mpic_irq_set_wake

[Wang Dongsheng]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Wednesday, September 23, 2015 7:50 AM
> To: Sudeep Holla
> Cc: linux-pm at vger.kernel.org; linux-kernel at vger.kernel.org; Thomas Gleixner;
> Rafael J. Wysocki; Benjamin Herrenschmidt; Paul Mackerras; Michael Ellerman; Jia
> Hongtao-B38951; Marc Zyngier; linuxppc-dev at lists.ozlabs.org; Wang Dongsheng-
> B40534
> Subject: Re: [PATCH 04/17] powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of
> redundant mpic_irq_set_wake
> 
> On Mon, 2015-09-21 at 16:47 +0100, Sudeep Holla wrote:
> > mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
> > flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
> > is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
> > as it doesn't guarantee wakeup for that interrupt.
> >

Non-freescale return -ENXIO, is there any issue? If non-freescale platform does
not support it, but IPs still use enable/disable_irq_wake, we should return a error number.

IRQCHIP_SKIP_SET_WAKE just skip this feature, this is not our expected.
If non-freescale platform need this flag to skip this feature, it should be add
in self platform.

@Scott:
If set this flag we cannot keep a irq as a wakeup source when system going to
SUSPEND or MEM.

irq_set_wake() means we can set this irq as a wake source.
IRQCHIP_SKIP_SET_WAKE is ignore irq_set_wake() feature.

Regards,
-Dongsheng