From: boris.brezillon@free-electrons.com (Boris Brezillon)
To: linux-arm-kernel@lists.infradead.org
Subject: at91sam9: watchdog: period
Date: Tue, 19 May 2015 11:14:02 +0200 [thread overview]
Message-ID: <20150519111402.747e8eb2@bbrezillon> (raw)
In-Reply-To: <555AFBFD.3010506@aksignal.cz>
On Tue, 19 May 2015 11:01:49 +0200
Ji?? Prchal <jiri.prchal@aksignal.cz> wrote:
>
>
> On 19.5.2015 09:14, Boris Brezillon wrote:
> > On Tue, 19 May 2015 11:07:29 +0800
> > "Yang, Wenyou" <wenyou.yang@atmel.com> wrote:
> >
> >>
> >>
> >> On 2015/5/18 16:17, Ji?? Prchal wrote:
> >>>
> >>>
> >>> On 18.5.2015 09:27, Boris Brezillon wrote:
> >>>>
> >>>> Can you dump watchdog registers (using devmem) ?
> >>>
> >>> / # devmem 0xfffffe40
> >>> 0x00000000
> >>> / # devmem 0xfffffe44
> >>> 0x1FFF2FFF
> >>> / # devmem 0xfffffe48
> >>> 0x00000000
> >>>
> >> The register value is right.
> >
> > It seems correct to me too.
> >
> Not to me, I want 4s:
> [ 4.675675] at91sam9_wdt: enabled (heartbeat=4 sec, nowayout=1)
There's a difference between your heartbeat (the frequency you
refresh/reset your watchdog) and the watchdog expiration time (here set
to 16 secs).
We usually set the heartbeat to 1/2 or 1/4 the expiration time, so that
we're (almost) sure we can reset the watchdog before its expiration.
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
next prev parent reply other threads:[~2015-05-19 9:14 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-15 7:16 at91sam9: watchdog: period Jiří Prchal
2015-05-15 13:59 ` Bryan Evenson
2015-05-15 14:19 ` Nicolas Ferre
2015-05-18 6:25 ` Jiří Prchal
2015-05-15 15:25 ` Boris Brezillon
2015-05-18 6:27 ` Jiří Prchal
2015-05-18 7:27 ` Boris Brezillon
2015-05-18 8:17 ` Jiří Prchal
2015-05-19 3:07 ` Yang, Wenyou
2015-05-19 7:14 ` Boris Brezillon
2015-05-19 9:01 ` Jiří Prchal
2015-05-19 9:14 ` Boris Brezillon [this message]
2015-05-19 9:52 ` Jiří Prchal
2015-05-19 10:04 ` Boris Brezillon
2015-05-20 12:39 ` Jiří Prchal
2015-05-21 12:41 ` Jiří Prchal
2015-05-27 7:11 ` Jiří Prchal
2015-05-19 7:12 ` Boris Brezillon
2015-05-19 9:00 ` Jiří Prchal
2015-10-06 13:07 ` Jiří Prchal
2015-10-06 18:03 ` Sylvain Rochet
2015-10-07 7:16 ` Jiří Prchal
2015-10-07 9:22 ` Sylvain Rochet
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