linux-kernel - Re: [PATCH 2/2] pinctrl: single: remove misuse of IRQF_NO

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Date:	Fri, 4 Dec 2015 16:26:39 +0000
From:	Sudeep Holla <sudeep.holla@....com>
To:	Grygorii Strashko <grygorii.strashko@...com>,
	Tony Lindgren <tony@...mide.com>
Cc:	Sudeep Holla <sudeep.holla@....com>,
	Linus Walleij <linus.walleij@...aro.org>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	linux-omap@...r.kernel.org
Subject: Re: [PATCH 2/2] pinctrl: single: remove misuse of IRQF_NO_SUSPEND
 flag



On 04/12/15 16:19, Grygorii Strashko wrote:
> On 12/04/2015 05:44 PM, Sudeep Holla wrote:
>>
>>
>> On 04/12/15 15:40, Tony Lindgren wrote:
>>> * Tony Lindgren <tony@...mide.com> [151203 13:41]:
>>>> * Sudeep Holla <sudeep.holla@....com> [151203 11:00]:
>>>>>
>>>>> I have added irq_set_irq_wake(pcs_soc->irq, state) in pcs_irq_set_wake
>>>>> which ensures it's marked for wakeup.
>>>>
>>>> Hmm well see the error I pasted in this thread, maybe that provides
>>>> more clues.
>>>
>>> The irq_set_irq_wake(pcs_soc->irq, state) in pcs_irq_set_wake does not
>>> look right to me as pcs_irq_set_wake toggles the irq_wake for each pin
>>> separately, not for the whole controller.
>>>
>>
>> OK, my understanding was that this driver supports multiple single
>> pinmux with one main irq `pcs_soc->irq`. Hence I added the wakeup on
>> that irq. I now think that understand is wrong.
>>
>
> With this change, PCS parent IRQ will be marked as wake up source as many
> times as many pins were requested as wake up IRQs (protected by counter).
> Most of all GPIO IRQ chips work this way.
> Of course, if we will look on pinctrl-single.c from only OMAP point of view
> then Prent IRQ can be marked as wake up source from probe only once.
> But, since this driver expected to be generic - this patch is more correct,
> because other HW may require to perform some real HW re-configuration to
> enable/disable wake up capabilities for Parent IRQ in Parent IRQ controller.
>

Thanks for the detailed explanation. I was bit confused if my
understanding is correct or not.

> Any way, in my opinion, it's right and more safe to manage all wakeup IRQs
> through IRQ PM core and Device wakeirq framework. And this patch should just
> go together with platform changes and not alone.
>

Agreed, since I don't have platform to test, I will leave it you guys to
pick up these patches when ready and with any changes if required.

-- 
Regards,
Sudeep
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