linux-kernel - Re: [PATCH 3/6] [RFC] rtc: rtc-cmos: Add pm_stay_awake/pm

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Date:	Sun, 2 Oct 2011 08:31:51 +1100
From:	NeilBrown <neilb@...e.de>
To:	John Stultz <john.stultz@...aro.org>
Cc:	lkml <linux-kernel@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>, arve@...roid.com,
	markgross@...gnar.org, Alan Stern <stern@...land.harvard.edu>,
	amit.kucheria@...aro.org, farrowg@...ibm.com,
	"Dmitry Fink (Palm GBU)" <Dmitry.Fink@...m.com>,
	linux-pm@...ts.linux-foundation.org, khilman@...com,
	Magnus Damm <damm@...nsource.se>, mjg@...hat.com,
	peterz@...radead.org
Subject: Re: [PATCH 3/6] [RFC] rtc: rtc-cmos: Add pm_stay_awake/pm_relax
 calls around IRQ

On Mon, 26 Sep 2011 12:13:51 -0700 John Stultz <john.stultz@...aro.org> wrote:

> Flag the rtc-cmos IRQ event as a wakeup event using pm_stay_awake
> and pm_relax()

It seems that only the 0/6 patch in this sequence was given any attention.
However it appears to me that 3, 4, and 5 stand on their own and are clearly
bug-fixes - the bug being that the wake-up event generated by the CMOS rtc is
not being counted as a wakeup event by the power core.

I'm less clear on 5, but that is probably simply that I don't understand this
code very well yet.

So maybe resend 4,5,6 by themselves and get them accepted?  Or maybe Rafael
could just pick them up and review/apply them as they are ???

Thanks,
NeilBrown


> 
> CC: Rafael J. Wysocki <rjw@...k.pl>
> CC: arve@...roid.com
> CC: markgross@...gnar.org
> CC: Alan Stern <stern@...land.harvard.edu>
> CC: amit.kucheria@...aro.org
> CC: farrowg@...ibm.com
> CC: Dmitry Fink (Palm GBU) <Dmitry.Fink@...m.com>
> CC: linux-pm@...ts.linux-foundation.org
> CC: khilman@...com
> CC: Magnus Damm <damm@...nsource.se>
> CC: mjg@...hat.com 
> CC: peterz@...radead.org 
> Signed-off-by: John Stultz <john.stultz@...aro.org>
> ---
>  drivers/rtc/rtc-cmos.c |   13 +++++++++++--
>  1 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
> index 05beb6c..1cc4688 100644
> --- a/drivers/rtc/rtc-cmos.c
> +++ b/drivers/rtc/rtc-cmos.c
> @@ -538,11 +538,15 @@ static struct bin_attribute nvram = {
>  
>  static struct cmos_rtc	cmos_rtc;
>  
> +static struct wakeup_source *rtc_cmos_wakelock;
> +
>  static irqreturn_t cmos_interrupt(int irq, void *p)
>  {
>  	u8		irqstat;
>  	u8		rtc_control;
>  
> +	__pm_stay_awake(rtc_cmos_wakelock);
> +
>  	spin_lock(&rtc_lock);
>  
>  	/* When the HPET interrupt handler calls us, the interrupt
> @@ -573,9 +577,12 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
>  
>  	if (is_intr(irqstat)) {
>  		rtc_update_irq(p, 1, irqstat);
> +		__pm_relax(rtc_cmos_wakelock);
>  		return IRQ_HANDLED;
> -	} else
> -		return IRQ_NONE;
> +	}
> +
> +	__pm_relax(rtc_cmos_wakelock);
> +	return IRQ_NONE;
>  }
>  
>  #ifdef	CONFIG_PNP
> @@ -1153,6 +1160,8 @@ static int __init cmos_init(void)
>  {
>  	int retval = 0;
>  
> +	rtc_cmos_wakelock = wakeup_source_register("rtc_cmos");
> +
>  #ifdef	CONFIG_PNP
>  	retval = pnp_register_driver(&cmos_pnp_driver);
>  	if (retval == 0)


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