[External] [PATCH] ALSA: hda/realtek - Add a model for Thinkpad T570 without DAC workaround

[Mark Pearson]

Hi

> -----Original Message-----
> From: Alsa-devel <alsa-devel-bounces at alsa-project.org> On Behalf Of
> Takashi Iwai
> Sent: Tuesday, May 26, 2020 2:24 AM
> 
> We fixed the regression of the speaker volume for some Thinkpad models
> (e.g. T570) by the commit 54947cd64c1b ("ALSA: hda/realtek - Fix
> speaker output regression on Thinkpad T570").  Essentially it fixes
> the DAC / pin pairing by a static table.  It was confirmed and merged
> to stable kernel later.
> 
> Now, interestingly, we got another regression report for the very same
> model (T570) about the similar problem, and the commit above was the
> culprit.  That is, by some reason, there are devices that prefer the
> DAC1, and another device DAC2!
> 
> Unfortunately those have the same ID and we have no idea what can
> differentiate, in this patch, a new fixup model "tpt470-dock-fix" is
> provided, so that users with such a machine can apply it manually.
> When model=tpt470-dock-fix option is passed to snd-hda-intel module,
> it avoids the fixed DAC pairing and the DAC1 is assigned to the
> speaker like the earlier versions.
> 
That's interesting - let me follow up with the HW team and see if I can
find out why this is. It would be nice to have something that works for 
all cases automatically.

Mark (Lenovo)