Re: [PATCH v2 3/3] pinctrl: cherryview: Ignore INT33FF UID 5 ACPI device

Andy Shevchenko
2021-11-26T18:23:21Z

On Thu, Nov 18, 2021 at 01:28:02PM +0200, Andy Shevchenko wrote:
> On Thu, Nov 18, 2021 at 11:56:50AM +0100, Hans de Goede wrote:
> > Many Cherry Trail DSDTs have an extra INT33FF device with UID 5,
> > the intel_pinctrl_get_soc_data() call will fail for this extra
> > unknown UID, leading to the following error in dmesg:
> >
> > cherryview-pinctrl: probe of INT33FF:04 failed with error -61
> >
> > Add a check for this extra UID and return -ENODEV for it to
> > silence this false-positive error message.
>
> Hmm... Interesting. Why do they have it?
> Give me some time to check this...

_DDN in ACPI describes this as Virtual GPIO. The only documentation at hand
right now tells me that this is a "solution" to represent the "virtual GPIO"
as fifth community (no connection to any pads, minimum configuration, etc).

The goal as far as I can see is "to convert a PME event generated by PCI device
to a GPIO interrupt".

Seems like we better have a driver for it, but the only purpose of it is to
generate interrupts based on PME.

I'll try to dig more may be next week, but for now I would like to postpone the
patch. Do you agree?