public inbox for linux-arm-kernel@lists.infradead.org
 help / color / mirror / Atom feed
From: boris.brezillon@free-electrons.com (Boris Brezillon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 1/2] dts: Documentation: AT91 Watchdog, explain what atmel,idle-halt property really do
Date: Thu, 22 Jan 2015 19:14:03 +0100	[thread overview]
Message-ID: <20150122191403.322059e3@bbrezillon> (raw)
In-Reply-To: <1421587611-32708-2-git-send-email-sylvain.rochet@finsecur.com>

On Sun, 18 Jan 2015 14:26:50 +0100
Sylvain Rochet <sylvain.rochet@finsecur.com> wrote:

> atmel,idle-halt property should be used with care, it actually makes the
> watchdog not counting when the CPU is in idle state, therefore the
> watchdog reset time depends on mean CPU usage and will not reset at all
> of the CPU stop working while it is in idle state, which is probably not
> what you want.
> 
> Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>

Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>

> ---
>  Documentation/devicetree/bindings/watchdog/atmel-wdt.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt b/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
> index f90e294..a4d8697 100644
> --- a/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
> +++ b/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
> @@ -26,6 +26,11 @@ Optional properties:
>  - atmel,disable : Should be present if you want to disable the watchdog.
>  - atmel,idle-halt : Should be present if you want to stop the watchdog when
>  	entering idle state.
> +	CAUTION: This property should be used with care, it actually makes the
> +	watchdog not counting when the CPU is in idle state, therefore the
> +	watchdog reset time depends on mean CPU usage and will not reset at all
> +	if the CPU stop working while it is in idle state, which is probably
> +	not what you want.
>  - atmel,dbg-halt : Should be present if you want to stop the watchdog when
>  	entering debug state.
>  



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

  reply	other threads:[~2015-01-22 18:14 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-17 21:49 [PATCH] AT91: DT: Watchdog, remove property idle halt by default Sylvain Rochet
2015-01-18  8:08 ` Boris Brezillon
2015-01-18 13:26   ` [PATCHv2 0/2] dts: AT91 " Sylvain Rochet
2015-01-18 13:26     ` [PATCHv2 1/2] dts: Documentation: AT91 Watchdog, explain what atmel, idle-halt property really do Sylvain Rochet
2015-01-22 18:14       ` Boris Brezillon [this message]
2015-01-18 13:26     ` [PATCHv2 2/2] dts: AT91 Watchdog, remove property idle halt by default Sylvain Rochet

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150122191403.322059e3@bbrezillon \
    --to=boris.brezillon@free-electrons.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox