linux-kernel - Re: [PATCH v3 2/2] watchdog: fix w83627hf

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Message-ID: <CAHyaeP1tdNpqtOLOYpy-OyL2_myPSQAO3eQF5_k9ryuFW6bhAQ@mail.gmail.com>
Date:	Wed, 3 Apr 2013 08:06:59 -0700
From:	Tony Chung <tonychung00@...il.com>
To:	Guenter Roeck <linux@...ck-us.net>
Cc:	Wim Van Sebroeck <wim@...ana.be>, linux-watchdog@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/2] watchdog: fix w83627hf_wdt clear timeout expired

On Tue, Apr 2, 2013 at 9:21 PM, Guenter Roeck <linux@...ck-us.net> wrote:

>
>
> What is the exact chip type in your system ? I want to have a look into the
> datasheet; maybe I can find out how it can trigger without causing a reset.

Winbond 83627HF chip

I believe BIOS has watchdog disabled otherwise it would have reboot the box.
However, the timer just start counting.

Comparing to ipmi_watchdog, you can do this:
modprobe ipmi_watchdog ... start_now=0 ...action=<>  nowayout=1

So it is possible to load the driver without start counting.

Notice it is an else, so t is actually 0 already (i.e. expired or
never start running):
> +     } else {
> +             outb_p(0, WDT_EFDR);    /* disable to prevent reboot */


--
- Tony Chung
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