Re: [PATCH v2 2/3] rtc: rx6110: add ACPI bindings to I2C

Andy Shevchenko
2020-11-16T16:04:52Z

On Mon, Nov 16, 2020 at 04:30:24PM +0100, Henning Schild wrote:
> Am Mon, 16 Nov 2020 16:46:31 +0200
> schrieb Andy Shevchenko <andriy.shevchenko@intel.com>:
>
> > On Thu, Nov 12, 2020 at 02:07:33PM +0100, Claudius Heine wrote:
> > > From: Johannes Hahn <johannes-hahn@siemens.com>
> > >
> > > This allows the RX6110 driver to be automatically assigned to the
> > > right device on the I2C bus.
> >
> > Before adding new ACPI ID, can you provide an evidence (either from
> > vendor of the component, or a real snapshot of DSDT from device on
> > market) that this is real ID?
> >
> > Before that happens, NAK.
> >
> > P.S. Seems to me that this is kinda cargo cult patch because proposed
> > ID is against ACPI and PNP registry and ACPI specification.
>
> In fact we pushed it in coreboot and Linux at the same time.
>
> https://review.coreboot.org/c/coreboot/+/47235
>
> That is the evidence. But in case this is wrong we can probably still
> change coreboot, even though the patches have been merged there already.

Yes, first of all you must follow ACPI and PNP registry. You may use your
Google vendor ID for that (IIRC you have two of them). Ideally you need to
convince Seiko Epson to do the right thing.

> Maybe you can go into detail where you see the violations and maybe
> even suggest fixes that come to mind.

Please, read ACPI specification. In particular chapters 6.1.2 "_CID
(Compatible ID)", 6.1.5 "_HID (Hardware ID)". The latter clarifies
the rules used to define an ID. Note, chapter 6.1.2 uses in particular
"A valid HID value".

I hope you are using as latest as possible ACPICA compiler (or at least
the one which follows the latest changes in it).

--
With Best Regards,
Andy Shevchenko