[U-Boot] [PATCH 4/4] udoo: fix watchdog setting

Giuseppe Pagano giuseppe.pagano at seco.com
Thu Nov 7 12:49:18 CET 2013


Hi Stefano,

On Thu, 2013-11-07 at 09:19 +0100, Stefano Babic wrote:
> Hi Giuseppe,
> 
> On 06/11/2013 21:44, Giuseppe Pagano wrote:
> > To have watchdog quiet during kernel boot it is necessary to
> > change gpio wdt trigger direction.
> > 
> 
> Sorry, this is not a good explanation. You force a GPIO to drop a
> feture, instead of disabling the feature itself. And maybe some other
> people want to have this feature enabled.
> 
> Which is the timeout for the watchdog ? Why is it hitting too soon ?
> 
> Fix should be not done simply removing the effect, but checking the cause.


I know, my explanation was poor. 
uDoo use APX823-31W5 as watchdog chip. Timeout is about 1.2 seconds. 
To disabled watchdog during kernel boot, WDI pin of that chip needs to
be in "high impedance" state. As far as I known mx6 gpio configuration
does not contemplate tristate, so the option I choose is to set pin as
input and in "high impedance". If wdt gpio is leaved as output che chip
resets.

> 
> Best regards,
> Stefano Babic
> 

Best regards,
Giuseppe Pagano



More information about the U-Boot mailing list