Re: [PATCH 1/2] ASoC: rt5677: Add ACPI device probing

Rafael J. Wysocki
2014-11-25T20:10:14Z

On Tuesday, November 25, 2014 11:07:06 AM Darren Hart wrote:
>
> On 11/25/14 10:43, Mark Brown wrote:
> > On Tue, Nov 25, 2014 at 10:33:01AM -0800, Darren Hart wrote:
> >> On 11/25/14 09:21, Mark Brown wrote:
> >
> >>> Given the design of _DSD is to share with DT and we already
> >>> have device tree bindings for the device we should be using,
> >>> it's not clear to me if we want to grind them all through UEFI
> >>> and I suspect they'd be unhappy if we tried but pretty much
> >>> all audio CODECs are good candidates for use with ACPI given
> >>> the new hardware designs Intel have so if we are doing it I
> >>> ought to be bouncing everyone to UEFI forum.
> >
> >> Right, I realized between sending and driving into the office
> >> that my statement might be construed this way. I meant *new*
> >> _DSD bindings should go through the ACPI/UEFI forum. Where we
> >> can reuse DT bindings, we should absolutely do that, agreed. We
> >> should still document this and link to the DT binding so it can
> >> be referenced and used even when Linux is not the target OS.
> >
> > Link from where - do we want to talk to the ACPI/UEFI forum and
> > figure out some kind of fast track process for them to add an
> > "it's already covered by DT, see here" entry to their database for
> > example? We also ought to work out how to make sure ACPI IDs are
> > registered there as well, should be possible to have something
> > simple as part of that.
> >
>
> This is a current topic with the ACPI working group. We have the
> following document:
>
> http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf
>
> I don't know if we want to have a list of them here, or if a separate
> document is needed. The important point is that it is independent from
> the ACPI specification itself so that it can be updated out of band
> with the specification, and not be subject to rather plodding pace
> that would imply.
>
> Rafael, I've missed several of these meetings unfortunately, and I'm
> not sure if we've closed on this point. Do you know?

This hasn't been discussed a lot at the meetings I attended.

The bindings management process is being set up within the UEFI Forum, but I'm
not sure if/how the existing DT bindings documented in the kernel tree are
going to be covered by it ATM.

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.