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To: Nick Hibma <nick@van-laarhoven.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Sun, 10 Dec 2006 16:10:23 +0100."
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Date: Sun, 10 Dec 2006 15:35:40 +0000
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Subject: Re: Slight interface change on the watchdog fido 
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In message <20061210160457.W42195@localhost>, Nick Hibma writes:
>>>   cognet@freebsd.org	i80321_wdog.c (*)
>>> (*) The i80321_wdog.c cannot be disarmed. Is this correct?
>>
>> If true, then this is a poster-child for the WD_PASSIVE need, the idea
>> being that if userland says "I'll not pat the dog anymore" and the hardware
>> cannot be disabled, the kernel shoul do it.
>
>~he implementation of the WD_PASSIVE part is on my list.
>
>I don't quite agree with you on the kernel taking over though. When 
>testing watchdogs you should be able to see that you could not disarm 
>it, as you would otherwise get mysterious hard reboots. I'd rather have 
>watchdogd refuse to exit if it cannot disarm the watchdog. I'll put that 
>on my list too.

Watchdog[d](8) may not be the only program that calls the ioctl, in
many embedded apps the central application will do so itself.

It seems to me a much more intuitive behaviour if the kernel takes
over the job of patting the offending piece of hardware.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.