Re: [PATCH 1/3] clocksource: atmel-st: Remove irq handler when clock event is unused

[Boris Brezillon]

Peter, Thomas,

On Sun, 2 Aug 2015 11:40:28 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Sun, Aug 02, 2015 at 11:10:21AM +0200, Thomas Gleixner wrote:
> > I think Boris Brezillon had implemented it at some point, but it was
> > shot down for reasons I can't remember. 
> 
> You weren't around at the time.. DT people didn't like it, said they
> didn't like having to make up fake hardware in their DT crap.

I don't know who was right, but the fact is they won't be inclined to
take such an approach unless the virtual demuxer is not exposed in the
DT, which is almost impossible since irq users are identifying their
irq lines with a phandle to the interrupt controller and an interrupt
id (usually extracted from the datasheet).

Anyway, below is a solution providing a way to disable specific
handlers without reworking the way we are modeling shared interrupts.
Thomas, I know you were not in favor of the proposed approach, but,
AFAICT, it does not add any conditional path to the interrupt handling
path (which, IIRC, was one of your requirements), and is simple enough
to be used by people really needing it.

There's probably other drawback I haven't noticed, so please don't
hesitate to share your thoughts.

Thanks,

Boris

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