Broken watchdog in u-boot master branch

[Pali Rohár]

On Monday 10 October 2022 12:28:18 Tom Rini wrote:
> On Sun, Oct 09, 2022 at 09:12:25PM +0200, Pali Rohár wrote:
> > Hello! Watchdog code seems to be broken in u-boot master branch.
> > On Nokia N900 I'm getting following message in qemu:
> > 
> > cyclic function rx51_watchdog took too long: 10000us vs 1000us max, disabling
> > 
> > Seems that watchdog core code is not prepared for "slower" watchdogs
> > which communicate over slower i2c bus, like it is the case for N900.
> > 
> > Disabling slower watchdog is a bad idea as it would result in reboot
> > loop instead of slower - but working code.
> 
> So, looking at this in more detail, we have
> CONFIG_CYCLIC_MAX_CPU_TIME_US as a configuration option (which is where
> the too long comes from). And picking a random CI run:
> https://source.denx.de/u-boot/u-boot/-/jobs/511177
> I do see we hit this in CI once, but not every time, QEMU runs here. Is
> that the max time is configurable enough to satisfy your concerns here?
> 
> -- 
> Tom

It is needed to investigate, how to _properly_ fix this issue, not just
workarounded it. Probably other boards may be affected.