On Sun, Oct 4, 2009 at 10:15 PM, Ingo van Lil <ing...@gmx.de> wrote: > On 10/04/2009 01:29 AM, Wolfgang Denk wrote: > >> No, not an exception, but the reference implementation. I cannot help >> it that most other architectures / SoCs don;t care much. > > Well, if such an uncommon side-effect is expected of a function with a > well-known name it should at least be prominently documented. I like > Mike's suggestion to have a central udelay() implementation for that; > I'm gonna try to whip up a patch tomorrow. > > >>> I'm using an Atmel AT91-based custom board, and the udelay() function >>> can be found in cpu/arm926ejs/at91/timer.c. Unfortunately there's no >>> central udelay() implementation in lib_arm. >> >> Guess nobody attempted to use a WD on such a system before. > > You hardly have a choice: After reset the AT91's watchdog timer runs at > maximum period (15 seconds), and the control register is one-time > writable. If you disable the watchdog in u-boot there's no way to > re-enable it later in the OS. > > Regards, > Ingo
Naive question of the day - Is there any reason for the complexity of the watchdog implementation with all the #defines to sort out software and hardware resets? Wouldn't it be easier to replace it with a weak function with an empty default implementation over-ridden at the board/arch/cpu level as needed? We can then call the watchdog reset in udelay() - will be a problem if the watchdog needs udelay (for a timed reset pulse for example) Just a thought Regards, Graeme _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
