[U-Boot] [PATCH 1/3] common/cmd_rsmode.c: add imx reset mode command

[Eric Nelson]

On 06/04/2012 12:52 PM, Wolfgang Denk wrote:
> Dear Eric Nelson,
>
> In message<4FC4DC4E.9030007 at boundarydevices.com>  you wrote:
>>
>> Writing a 4 to the WDOG_BASE register enables the watchdog with a 1/2s delay.
>> I think there should be a delay or while(1) loop afterwards though. It appears
>> that the reset_cpu() routine will return.
>
> I recommend NOT messing with the watchdog for any unrelated functions.
>
> The function of the watchdog should be reserved for auch systems who
> need it to implement security related functions; messing with it in
> unrelated places (like setting it into unexpected states and or
> timeouts) may cause undefined behaviour on such systems.
>
> Don't do it.
>

Hi Wolfgang,

My comment is that reset_cpu() should probably not return, and
at the moment it will. The minimum WDT timeout value is 1/2 second, so
execution will continue for some time less than that.

It seems to me that this might be a bad thing, allowing unexpected
execution of commands in a script after the execution of the 'reset'
command.

If I understand your comment, you're saying that reset_cpu() should
not be implemented using the watchdog.

Is that right?

Please advise,


Eric