Re: [PATCH] irqchip: gic: Allow interrupt level to be set for PPIs.

From: Russell King - ARM Linux
Date: Mon Dec 01 2014 - 06:04:18 EST


On Mon, Dec 01, 2014 at 10:46:13AM +0000, Liviu Dudau wrote:
> On Mon, Dec 01, 2014 at 10:41:45AM +0000, Russell King - ARM Linux wrote:
> > On Fri, Nov 28, 2014 at 05:55:40PM +0000, Liviu Dudau wrote:
> > > + /*
> > > + * PPIs are optionally configurable, but we cannot distinguish
> > > + * between high and low, nor falling and rising. Change the
> > > + * type so that it passes the next check.
> >
> > This comment could do with a /lot/ of improvement. It sounds like the
> > only reason this code exists is to bypass the check. If that's all
> > that's being done, there's better ways to code it.
>
> Hi Russell,
>
> You are right, all I want to do is bypass the next check because *if*
> the PPIs can be configured, then any combination is valid (edge
> raising/falling, level low/high). In real systems, PPIs tend to be
> configured with active level low. That falls the existing check.

"fails" :)

If all you want to do is to bypass the following check, what's wrong
with actually doing that:

- if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
+ if (gicirq >= 32 && type != IRQ_TYPE_LEVEL_HIGH &&
+ type != IRQ_TYPE_EDGE_RISING)
return -EINVAL;

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