[Skiboot] [PATCH 3/3] ipmi/wdt: Add ipmi watchdog timer support

[Alistair Popple]

On Thu, 29 Jan 2015 16:08:12 Benjamin Herrenschmidt wrote:
> On Thu, 2015-01-29 at 12:59 +0800, Jeremy Kerr wrote:
> > Hi Ben,
> > 
> > > Or we just set the pre-timeout interrupt always and use it as the
> > > watchdog tickle.
> > 
> > The downside here is that we'd then have a periodic IPMI transaction,
> > which may introduce jitter. I'd prefer to leave it up to the OS to
> > enable - there's the IPMI watchdog in the kernel, which is capable of
> > handling this.
> > 
> > The downside is that the watchdog won't "watch" the period between OPAL
> > platform init (where we handle the first interrupt) and watchdog driver
> > init, but I think that's a reasonable compromise.
> 
> I'm not sure ... the watchdog driver init will typically be in the
> initramfs or root disk, lots of things can go wrong...

One of the problems I ran into when leaving the WDT enabled was that the 
system would actually become *less* reliable due to transient communication 
errors with a certain other system component that I haven't been able to 
debug...

> Ben.
> 
> > Cheers,
> > 
> > 
> > Jeremy