Re: [PATCH 0/2] Fix CSC3551 speaker sound problem for machines without a valid ACPI _DSD

[David Xu <xuwd1@hotmail.com>]

On Mon, 17 Jul 2023 13:48:28 +0100, Stuart Henderson wrote:
> On 16/07/2023 13:49, Takashi Iwai wrote:
> > On Thu, 13 Jul 2023 18:29:53 +0200,
> > David Xu wrote:
> >>
> >> As the comments added in commit 4d4c4bff4f8ed79d95e05 ("ALSA: hda:
> >> cs35l41: Clarify support for CSC3551 without _DSD Properties"), CSC3551
> >> requires a valid _DSD to work and the current implementation just
> >> fails when no _DSD can be found for CSC3551. However it is a fact
> >> that many OEMs hardcoded the configurations needed by CSC3551 into their
> >> proprietary software for various 2022 and later laptop models,
> >> and this makes the Linux installations on these models cannot make
> >> any speaker sound. Meanwhile, at this point of time, we see no hope
> >> that these OEMs would ever fix this problem via a BIOS update.
> >>
> >> To address the problem, this patch series contains two patches:
> >>
> >> Patch 1 for cs35l41 hda driver: a fixup mechanism is introduced that
> >> when the driver found there is no valid _DSD that contains the
> >> configurations, a fixup function would try to find a fixup entry that
> >> contains a proper cs35l41 configuration from a pre-defined fixup table
> >> by matching the CSC3551 ACPI _SUB id. If found, the fixup function
> >> would apply the cs35l41 configurations retrived from the entry.
> >> In this patch the fixup table only contains some entries for three
> >> Lenovo laptop models: namely 16IAH7, 16IAX7 and 16ARHA7. However
> >> as is known, several other laptop models from ASUS and HP also suffer
> >> from this no valid _DSD problem and could have it addressed with this
> >> fixup mechanism when proper fixup entries are inserted.
> >>
> >>
> >> Patch 2 for realtek hda driver: add quirks for Lenovo 16IAH7, 16IAX7
> >> and 16ARHA7 so that cs35l41 playback hook could be registered. Please
> >> note that for these quirks to work patch 1 has to be applied.
> > Thanks for the patches.
> >
> > I've seen the lots of pains with CS35L41 codec stuff on the recent
> > machines.  But, first of all, it still needs to be agreed by Cirrus
> > people whether this approach is acceptable.  Judging from the current
> > situation, such workaround appears inevitable, but we need a
> > consensus.
> >
> > So, Cirrus people, please check this.
> >
> >
> > Also, some ideas about the current patch set:
> >
> > - Do we need yet another listing and check of each ID in another
> >    place?  The existing entry in the SSID quirk table is already unique
> >    enough to identify which configuration is taken, I suppose.
> >
> > - The quirk entries can be gathered in patch_realtek.c, and the hw_cfg
> >    and other items are overwritten in cs35l41_no_acpi_dsd() when no
> >    _DSD is found.  In that way, we can avoid fixing two places for each
> >    update.
> >
> > - The workaround is a workaround, and it's fundamentally dangerous.
> >    We should warn it in a kernel message.
> >
> >
> > Takashi
> 
> Hi David, Takashi,
> We're looking into supporting some of these older devices at the moment, 
> and have a patch chain in development at the moment.
> The approach we've taken is a lot closer to the one taken by the github 
> Luke links through to elsewhere in this chain, which we think might be a 
> cleaner approach.  We do have concerns about the current approach of 
> identifying the SPI device though, as we've seen "spi1" become "spi2" as 
> additional devices become supported in the kernel and more SPI 
> controllers come into use.  We'll look into this more and hopefully get 
> a patch chain up in the coming weeks.
> This patch chain looks like it might also be missing support for 
> different boost configurations.
> I wouldn't recommend this patch be merged.
> Thanks,
> Stu

Hi Stuart,

Thank you for replying. I am looking forward to your work for fixing
this problem and hopefully I could see it in the following weeks. In 
addtion I'd like to justify this lack of support for boost configurations
as without a valid _DSD, it is nearly impossible for us users to know the 
correct and safe configuartion for internal boosting. The current situation
is that without this boosting config, we indeed get a quite low speaker
sound. It would be much appreciated if you could also solve this problem. 

Regards,

David