Re: how to allow board writers to customize driver behavior (watchdog here)

["Mike Frysinger" <vapier.adi@gmail.com>]

On 5/25/07, Daniel Newby <daniel.a.newby@gmail.com> wrote:
> On 5/24/07, Paul Mundt <lethal@linux-sh.org> wrote:
> > So far the only example anyone has provided outside of periodic timers or
> > hardware reset has been dumping the stack when something gets stuck.
> > Softlockup does this already today, using a timer.
>
> Many watchdogs can be hooked up to a non-maskable interrupt (NMI) that
> cannot be disabled or preempted.  You get a stack dump even for drastic
> bugs:  ISR lock up, timer misconfiguration, level-sensitive interrupt
> line stuck asserted, and so forth.  Getting that information by other
> means can be painful and/or expensive.
>
> The Blackfin chip in the original message appears to support watchdog
> NMI.

it does ... it has four modes:
 - reset (drivers/char/watchdog/bfin_wdt.c)
 - interrupt (i'll prob write a clockevents driver for this)
 - NMI (no plans to do anything for this as NMI is unused in Blackfin)
 - nothing (have yet to find a use case for this)
-mike