Re: [PATCH 1/2] i2c: acpi: skip generic I2C device when vendor-specific sibling exists

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Mon, Mar 16, 2026 at 02:32:42PM +0000, Edward Blair wrote:
> On Sun, 16 Mar 2026 at 13:12, Mika Westerberg wrote:
> > Are they both 'present'? I mean their _STA() returns 0xF for both?
> 
> MSFT8000:00 has no _STA method at all. The sysfs status attribute is
> absent, which only happens when acpi_has_method(handle, "_STA")
> returns false (device_sysfs.c line 591). So it defaults to present per
> the ACPI spec. ITE8853:00 has _STA returning 0xF.

Okay.

> As Heikki pointed out, MSFT8000 is the RhProxy device, not UCSI. My
> mistake in the commit message.
> 
> > We have a quirk table already in drivers/acpi/x86/utils.c that I
> > think could be used to mark the other one being not present.
> 
> That would work. acpi_device_override_status() runs before _STA
> evaluation so it can force status=0 even without a _STA method.
> 
> My concern is scope. MSFT8000 is a Windows-only Resource Hub Proxy
> (RhProxy) device with no Linux driver, no module binding, and no
> in-kernel consumer. It's a static ACPI node with no _STA, so the
> BIOS exports it unconditionally. Skipping it during I2C client
> enumeration would have zero functional impact on Linux while avoiding
> a quirk table entry that needs duplicating per board.

Well it needs to be somewhere unfortunately :( Gathering these into one
file at least makes it sligthly more maintainable IMHO. I think the
override_status_ids could be made to use only the HID so no need to add DMI
strings. Of course if we ever want to bind a driver to it then it needs to
be exposed again (but that sounds unlikely since we already have a real
device that a driver could bind to).

Just my 2 cents.