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Date: Tue, 9 Aug 2005 15:01:31 -0700
From: Andrew Morton <akpm@osdl.org>
To: Kumar Gala <galak@freescale.com>
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Cc: linux-kernel@vger.kernel.org, linuxppc-embedded@ozlabs.org
Subject: Re: [PATCH] ppc32: Added support for the Book-E style Watchdog Timer
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Kumar Gala <galak@freescale.com> wrote:
>
> PowerPC 40x and Book-E processors support a watchdog timer at the processor
> core level.  The timer has implementation dependent timeout frequencies
> that can be configured by software. 
> 
> One the first Watchdog timeout we get a critical exception.  It is left
> to board specific code to determine what should happen at this point.  If
> nothing is done and another timeout period expires the processor may
> attempt to reset the machine.
> 
> Command line parameters:
>   wdt=0 : disable watchdog (default)
>   wdt=1 : enable watchdog
> 
>   wdt_period=N : N sets the value of the Watchdog Timer Period.
> 
>   The Watchdog Timer Period meaning is implementation specific. Check
>   User Manual for the processor for more details.
> 
> This patch is based off of work done by Takeharu Kato.
> 
> ...
> 
> +#ifdef CONFIG_BOOKE_WDT
> +/* Checks wdt=x and wdt_period=xx command-line option */
> +int __init early_parse_wdt(char *p)
> +{
> +	extern u32 wdt_enable;
> +
> +	if (p && strncmp(p, "0", 1) != 0)
> +	       wdt_enable = 1;
> +
> +	return 0;
> +}
> +early_param("wdt", early_parse_wdt);
> +
> +int __init early_parse_wdt_period (char *p)
> +{
> +	extern u32 wdt_period;
> +
> +	if (p)
> +		wdt_period = simple_strtoul(p, NULL, 0);
> +
> +	return 0;
> +}


Would prefer to see the declaration of wdt_period in a header file, please.

But beware that wdt_enable() is already a static symbol in a couple of
watchdog drivers.  It might be best to rename the ppc global to something
less generic-sounding while you're there.