[PATCH] ALSA: hda/realtek: Add quirk for Lenovo Ideapad S740

[Takashi Iwai]

On Fri, 16 Apr 2021 18:05:17 +0200,
Pierre-Louis Bossart wrote:
> 
> 
> 
> On 4/16/21 3:47 AM, Jaroslav Kysela wrote:
> > Dne 16. 04. 21 v 10:12 Takashi Iwai napsal(a):
> >> Lenovo Ideapad S740 requires quite a few COEF setups to make its
> >> speakers working.  The verb table was provided from Ryan Prescott as
> >> the result of investigation via qemu:
> >>    https://github.com/ryanprescott/realtek-verb-tools/wiki/How-to-sniff-verbs-from-a-Windows-sound-driver
> >
> > [Cc: to Kailang / Realtek]
> >
> > I believe that this sequence contains I2C writes to amplifier chips. It would
> > be really helpful, if Realtek can provide more information for the I2C master
> > interface for their codecs (describe basic I2C I/O).
> 
> The biggest problem is to figure what address/value pairs to write
> with I2C into the amplifiers, and here the catch is that those I2C/I2S
> amplifiers may or may not be sourced from Realtek, and it'd be
> difficult for Realtek to provide documentation on their competition,
> wouldn't it?

Sure, that's another problem.  But currently it's not clear even how
to communicate via I2C/whatever to the underlying chip, as it's done
via the vendor-specific COEF verb.  At least this could be opened, I
hope.


Takashi