[PATCH v2] arm64: errata: Handle Apple WFI State Loss

Will Deacon will at kernel.org
Fri Jun 19 02:24:54 PDT 2026


On Wed, Jun 17, 2026 at 09:23:03PM +0200, Yureka Lilian wrote:
> On 6/15/26 17:02, Will Deacon wrote:
> > In fact, would wfe be a better choice than nop for you?
> 
> Regarding wfe: Simply replacing the wfi with wfe on these particular
> machines leads to them getting stuck in the boot process (entering wfe on
> the boot core and never waking up again), maybe because some kinds of
> interrupts do not count as as events for the wfe wake-up?

argh, I had forgotten that a pending masked interrupt doesn't wake up
a WFE (it does wake up a WFI).

So we probably shouldn't have wfe in the list of idle instruction choices
(unless we want to rely on the eventstream).

Will



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