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Date: Mon, 1 Mar 2010 12:10:07 +0100
From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
	<u.kleine-koenig@pengutronix.de>
To: Alessandro Zummo <a.zummo@towertech.it>
Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org,
       Paul Gortmaker <p_gortmaker@yahoo.com>,
       Andrew Morton <akpm@linux-foundation.org>,
       Valentin Longchamp <valentin.longchamp@epfl.ch>,
       Sascha Hauer <s.hauer@pengutronix.de>
Subject: Re: [rtc-linux] [PATCH 6/6] rtc/mc13783: implement alarm
Message-ID: <20100301111007.GD16049@pengutronix.de>
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On Mon, Mar 01, 2010 at 11:56:25AM +0100, Alessandro Zummo wrote:
> On Mon,  1 Mar 2010 11:53:45 +0100
> Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
> 
> > for now this just ignores the possible race to trigger an alarm when
> > setting the time.  Should I resolve that, if so, what is the prefered
> > way to do that?
> 
>  I saw you email on the topic but I haven't had
>  the time to answer appropriately. 
> 
>  I'd suggest to disable the alarm irq while setting
>  the time.
I have two possibilities, I'm not sure if you mean the first or just any
of the two:

  1)
	pending = is_alarm_pending
	mask_alarm_irq
	set time and date
	if (!pending)
		ack_alarm_irq
	unmask_alarm_irq

  2)
	alarmtime = read_alaram
	program_alarm(invalid)
	set time and date
	program_alarm(alarmtime)

I'd prefer 2), is that OK for you, too?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |