Re: [PATCH 13/17] net: gianfar: remove misuse of IRQF_NO_SUSPEND flag

On 22/09/15 15:04, Manoil Claudiu wrote:

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From: Thomas Gleixner [mailto:tglx@linutronix.de]

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on PPC architectures, the flag did the job.  When did this change? Since
when using IRQF_NO_SUSPEND is a "misuse"?

It always was. Simply because IRQF_NO_SUSPEND has absolutely nothing
to do with wakeup interrupt sources. It's a flag which excludes the
interrupt from the suspend mechanism, but it does not flag it a wakeup
source.

I'm seeing also a "powerpc: mpic" patch in the series, unfortunately I can't

Yes I think that was a redundant code, so I removed it. IIRC it was
setting IRQF_NO_SUSPEND in irq_set_wake callback which again is incorrect.

afford to test it right now. However I ran a quick test with this gianfar patch
in isolation on a powerpc system, and seen some difference in the behavior
(with and w/o the patch).  In both cases the system wakes up from standby
by magic packet.  However, without the IRQF_NO_SUSPEND flag 2 wake-up
interrupts are reported in /proc/interrupts for one magic packet; with the

OK that's interesting, will have check if I have similar behavior on my
setup too.

flag on there's just 1 interrupt.  Maybe this is not relevant, maybe the
"powerpc: mpic" patch from this series changes this behavior.

Hmm not sure, but better to test it together if possible. If required we
can reorder for bisect-ability reasons.

But if this is the API, what can I say? We'll see in time.  Btw, enable_irq_wake()
returns an error code, normally it should be handled by printing a warning
message at least, right?  But since most drivers don't handle that, I'm assuming
it should be left unhandled to avoid overcomplicating things.

Yes I left it so that I can add if the maintainer insist and not churn
too much code adding warning.

FWIW
Acked-by: Claudiu Manoil <redacted>

Thanks.

Regards,
Sudeep