Re: [PATCH v1 6/8] x86: rtc: Drop PNP device check

[Rafael J. Wysocki]

On Wed, Feb 25, 2026 at 7:01 PM Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>
> On 2/23/26 07:31, Rafael J. Wysocki wrote:
> > Previous changes effectively prevented PNP devices from being created
> > for the CMOS RTC on x86 with ACPI.
> >
> > Although in principle a CMOS RTC PNP device may exist on an x86 system
> > without ACPI (that is, an x86 system where there is no ACPI at all, not
> > one booted with ACPI disabled), such systems were there in the field ~30
> > years ago and most likely they would not be able to run a contemporary
> > Linux kernel.
> >
> > For the above reasons, drop the PNP device check from add_rtc_cmos().
>
> If someone had one of these devices, what would they see after applying
> this? Would they just not be able to detect the RTC any longer?

No, add_rtc_cmos() would just create a fallback platform device for
the CMOS RTC AFAICS and the driver would pick up that one.

> In any case, this does seem obscure enough to not worry about any more:
>
> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> # x86

Thanks!