linux-kernel - Re: [RFC 2/2] clocksource: don't suspend/resume when unused

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Date:	Fri, 16 Jan 2015 11:59:33 +0100
From:	Daniel Lezcano <daniel.lezcano@...aro.org>
To:	Alexandre Belloni <alexandre.belloni@...e-electrons.com>
CC:	Thomas Gleixner <tglx@...utronix.de>,
	John Stultz <john.stultz@...aro.org>,
	Nicolas Ferre <nicolas.ferre@...el.com>,
	Boris Brezillon <boris.brezillon@...e-electrons.com>,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC 2/2] clocksource: don't suspend/resume when unused

On 01/16/2015 11:48 AM, Alexandre Belloni wrote:
> Hi,
>
> On 16/01/2015 at 11:39:16 +0100, Daniel Lezcano wrote :
>>> Isn't that already the case?
>>> Right now, if you call clocksource_suspend, it doesn't matter whether
>>> the clocksource has an enable or not, it will be suspended. Maybe I'm
>>> mistaken but my patch doesn't seem to change that behaviour.
>>
>> Actually, if there is no enable/disable callback, then CLOCK_SOURCE_USED
>> will be never set, hence the condition will always fail and the suspend
>> callback won't be called.
>>
>
> It is set in clocksource_enable/disable, even if there is no
> enable/disable callback.

Ah, right. But shouldn't we set the flag only if the callback is present 
and succeed as Boris mentioned it ?

> I only found direct calls to ->enable() in
> timekeeper.c, did I miss some?




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