[U-Boot] [PATCH v4] at91: Don't initialize watchdog if CONFIG_SKIP_WATCHDOG_INIT is defined

[Mike Frysinger]

On Mon, Aug 9, 2010 at 2:40 AM, Alexander Stein wrote:
> On AT91 the watchdog mode register can only be written once after reset.
> If this register is written by u-boot e.g. a Linux driver can't
> reconfigure the watchdog later. If the watchdog is left untouched this
> is possible. Without touching the mode register the watchdog has a default
> setup and u-boot is still able to trigger the watchdog.
>
> Signed-off-by: Alexander Stein <alexander.stein at systec-electronic.com>
> ---
> Changes in v2:
> * Add a new specific option CONFIG_SKIP_WATCHDOG_INIT
> * Add some documentation
>
> Changes in v3:
> * Be more verbose in describing the problem in the commit message and README
>
> Changes in v4:
> * Fix commit message
>
>  README                                      |   11 +++++++++++
>  arch/arm/cpu/arm926ejs/at91/lowlevel_init.S |    2 ++
>  2 files changed, 13 insertions(+), 0 deletions(-)
>
> diff --git a/README b/README
> index b6bf451..9fbb6c9 100644
> --- a/README
> +++ b/README
> @@ -2827,6 +2827,17 @@ Low Level (hardware related) configuration options:
>                some other boot loader or by a debugger which
>                performs these initializations itself.
>
> +- CONFIG_SKIP_WATCHDOG_INIT
> +
> +               [arm AT91 only] If this variable is defined, then the
> +               watchdog will not be programmed upon u-boot start.
> +               On AT91 the watchdog mode register can only be written
> +               once after reset. If this register is written by u-boot
> +               e.g. a Linux driver can't reconfigure the watchdog later. If
> +               the watchdog is left untouched this is possible.
> +               Without touching the mode register the watchdog has a default
> +               setup and u-boot is still able to trigger the watchdog.

isnt the at91 logic inverted ?  shouldnt the watchdog programming only
be done when someone has opted in to it via some watchdog define ?
-mike