[PATCH 0/3] watchdog: honour hw_margin_ms property

Rasmus Villemoes rasmus.villemoes at prevas.dk
Mon Mar 16 16:52:06 CET 2020

On 14/03/2020 13.04, Stefan Roese wrote:
> On 13.03.20 17:04, Rasmus Villemoes wrote:

>> That at least solves half my problems and
>> might be useful to others as well. Then I'll have to figure out the
>> time-stands-still problem in some other way.
> If its too hard to enable interrupts in SPL for you or to provide some
> other means of a working get_timer() API, then we needto find another
> solution. You started with this weak function, which of course works.
> What other options are there? Adding a callback mechanism to register
> platform specific callback functions? Even though this might get a
> little bit too complicated.

Now that I dig a bit more into this, I seem to remember that we actually
also had problems in U-Boot proper when loading a compressed kernel, so
for now we're using an uncompressed kernel in our FIT images. I will
have to re-investigate, but it now occurs to me that it might be due to
the fact that interrupts get disabled during bootm (which makes sense,
the same reason I stated previously of interrupt vectors about to be
overwritten), so even in U-Boot proper, time as measured by get_timer()
ceases to pass after that point, so all the WATCHDOG_RESET() calls from
the inflate code effectively get ignored.

So it may be necessary to have some wdt_ratelimit_disable() hook that
can be called from bootm_disable_interrupts() and e.g. some
board-specific SPL code. I'll do some experiments and figure out if I do
indeed need such a hook.


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