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

From: Marc Zyngier
Date: Mon Dec 01 2014 - 06:19:56 EST


Hi Russell,

On 01/12/14 11:03, Russell King - ARM Linux wrote:
> 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;
>

I think that will require some additional changes to gic_configure_irq
(in irq-gic-common.c).

Thanks,

M.
--
Jazz is not dead. It just smells funny...
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