linux-kernel - Re: [PATCH v9 1/1] irqchip: imx-gpcv2: IMX GPCv2 driver for wakeup sources

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Date:	Tue, 25 Aug 2015 15:45:56 +0100
From:	Sudeep Holla <sudeep.holla@....com>
To:	Shenwei Wang <Shenwei.Wang@...escale.com>
CC:	Sudeep Holla <sudeep.holla@....com>,
	"shawn.guo@...aro.org" <shawn.guo@...aro.org>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"jason@...edaemon.net" <jason@...edaemon.net>,
	Huang Anson <Anson.Huang@...escale.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v9 1/1] irqchip: imx-gpcv2: IMX GPCv2 driver for wakeup
 sources



On 25/08/15 15:14, Shenwei Wang wrote:
>
>
>> -----Original Message-----
>> From: Sudeep Holla [mailto:sudeep.holla@....com]

[...]

>> I don't see this driver doing anything extra apart from keeping the wakeup irqs
>> enabled. i.e. You use the same cpu*wake register to mask/unmask the interrupt
>> as well as set the wakeup source. Since the wakeup interrupt will be enabled by
>> the driver, you just need to mark it as wake-up source and nothing extra in the
>> controller right ?
>> If so, you need to set IRQCHIP_SKIP_SET_WAKE as you are just leaving that irq
>> enabled and not doing any extra configuration to enable it as wakeup source.
>> Please correct if that wrong, but from the code that's what I could infer.
>
> There is no special for this driver. We just use the IRQCHIP driver framework to
> manage the wakeup sources. Why did you propose to set IRQCHIP_SKIP_SET_WAKE
> flag here? If you don't need the wakeup feature, you should just not enable this
> driver in the configuration.
>

No, if the driver doesn't nothing extra to configure the wake up source
other than keeping it enabled, then it fits the case of SKIP_SET_WAKE.
The driver using this wake would have requested and enabled the irq.
When it calls enable_irq_wake, you have nothing extra to set(atleast
from the looks of the driver), so setting SKIP_SET_WAKE will skip the
call and updated the wake flags in irq core.

I don't see the real need of 2 separate sets of irq mask being saved in
either case.

Regards,
Sudeep
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