From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wolfgang Denk <wd@denx.de>
Date: Tue, 20 Mar 2007 13:10:24 +0100
Subject: [U-Boot-Users] CONFIG_HW_WATCHDOG in 1.1.6
In-Reply-To: Your message of "Tue, 20 Mar 2007 09:56:28 +0100."
	<45FFA1BC.2040809@gmx.net> 
Message-ID: <20070320121024.A672C35261B@atlas.denx.de>
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In message <45FFA1BC.2040809@gmx.net> you wrote:
>
> What's the preferred policy to trigger the watchdog in U-Boot? Trigger 
> using a timer interrupt (as in lib_ppc/interrupts.c) or add calls to 
> WATCHDOG_RESET() to every function which may take longer than some 
> fraction of the minimal watchdog period (which is?)?

The minimal watchdog period we've seen in real systems so far  is  80
milliseconds, including some tolerance of +/- 20%, so we need to keep
it < 50 millisec.

Normally, we trigger the WD in the timer tick  (i.  e.  every  milli-
second);  additionally,  we  have  a  WD  trigger in udelay(), so any
(possibly long) delays based on this are automatically safe.

This should reduce the number of places where a manual WATCHDOG_RESET
is needed to very few.

> I know there are functions which disable interrupts and thus have to 
> trigger the watchdog themself (like do_bootm).

I think most of these places are already safe.

Best regards,

Wolfgang Denk

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