Re: [PATCH v3 2/2] ALSA: hda/tas2781: Add tas2781 HDA driver

Andy Shevchenko
2023-08-21T09:06:30Z

On Sun, Aug 20, 2023 at 11:16:08AM +0200, Takashi Iwai wrote:
> On Fri, 18 Aug 2023 19:01:16 +0200,
> Andy Shevchenko wrote:
> > On Fri, Aug 18, 2023 at 11:00:34AM -0500, Pierre-Louis Bossart wrote:

...

> > > > +static void tas2781_fixup_i2c(struct hda_codec *cdc,
> > > > + const struct hda_fixup *fix, int action)
> > > > +{
> > > > + tas2781_generic_fixup(cdc, action, "i2c", "TIAS2781");
> > >
> > > TI ACPI ID is TXNW
> > >
> > > https://uefi.org/ACPI_ID_List?search=TEXAS
> > >
> > > There's also a PNP ID PXN
> > >
> > > https://uefi.org/PNP_ID_List?search=TEXAS
> > >
> > > "TIAS" looks like an invented identifier. It's not uncommon but should
> > > be recorded with a comment if I am not mistaken.
> > >
> > > > +}
> >
> > Thank you, but actually it's a strong NAK to this even with the comment.
> > We have to teach people to follow the specification (may be even hard way).
> >
> > So where did you get the ill-formed ACPI ID?
> > Is Texas Instrument aware of this?
> > Can we have a confirmation letter from TI for this ID, please?
>
> This is used already for products that have been long in the market,
> so it's way too late to correct it, I'm afraid.
>
> What we can do is to get the confirmation from TI, complain it, and
> some verbose comment in the code, indeed.

Oh, no! Who made that ID, I really want to point that at their faces.
Look at the Coreboot (successful) case, they created something, but
in time asked and then actually fixed the ill-formed ID (that was for
one of RTC chips).

For this, please make sure that commit message has that summary, explaining that
- states that ID is ill-formed
- states that there are products with it (DSDT excerpt is a must)
- lists (a few?) products where that ID is used
- ideally explains who invented that and Cc them to the patch, so they will
know they made a big mistake

--
With Best Regards,
Andy Shevchenko