Re: [REGRESSION] ACPI processor/cpuidle change in 6.18.52 breaks bare-metal Xen dom0 boot

[Rafael J. Wysocki (Intel)]

On Mon, Sep 21, 2026 at 7:46 PM Support TRINITY <support@xxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> Thank you, this matches what I see on the affected Alpine Xen dom0
> systems.
>
> I also tested Linux 6.18.52 with processor=nocst on the Linux kernel
>
> Result: it still fails with the same black screen before dom0 userspace
> and networking come up.
>
> Marek's trace looks consistent with the failure mode I isolated: the
> crash happens from acpi_processor_power_init() while registering the
> cpuidle device.

I think I know what the problem is, see

https://lore.kernel.org/linux-acpi/CAJZ5v0h4giv53a2mPvJYT=fvBTj7vVXs=b7+qC2Q2L35qSTOSA@xxxxxxxxxxxxxx/