Re: [PATCH 2/2] cyclic: return early from cyclic_run() if the list is empty

On 7/30/26 12:55, Rasmus Villemoes wrote:

> It is possible that schedule(), and hence cyclic_run(), gets called
> very early, perhaps even from assembly code. With commit
> 9c1b13b3fd2 ("cyclic: reduce get_timer_us() calls inside
> hlist_for_each_entry_safe()"), there is now an unconditional
> get_timer_us(0) done outside the loop, and depending on the platform,
> the timer infrastructure may not be set up yet. In at least one case,
> that has caused a divide-by-0 and hence a failure to boot.
>
> Platforms should really ensure their timers are ready ASAP, and in the
> concrete case reported, that was indeed possible to fix that
> way. However, it doesn't hurt to also insert an early return here, and
> that could prevent other such hard-to-debug boot failures.
>
> Reported-by: Emanuele Ghidoli <[email protected]>
> Link: https://marc.info/?l=u-boot&m=178481834846283&w=2
> Fixes: 9c1b13b3fd2 ("cyclic: reduce get_timer_us() calls inside hlist_for_each_entry_safe()")
> Signed-off-by: Rasmus Villemoes <[email protected]>

Applied to u-boot-watchdog/main, with a fixup while applying:

  [sr: fix Fixes: tag SHA length and return statement indentation]

Thanks,
Stefan