[alsa-devel] [RFC] hda/realtek filtered headphone output

[Takashi Iwai]

[ corrected to the right ML ]

On Thu, 23 Aug 2018 14:37:39 +0200,
René Rebe wrote:
> 
> Hi,
> 
> On 23 Aug 2018, at 14:31, Takashi Iwai <tiwai at suse.de> wrote:
> 
> > On Thu, 23 Aug 2018 13:10:39 +0200,
> > René Rebe wrote:
> >> 
> >> Hi Takashi,
> >> 
> >> I uploaded the requested log but did not hear back.
> >> The limited headphone frequency response (aka high-pass) is still an issue with 4.18.
> >> I rebased the patch:
> >> 
> >> 	https://svn.exactcode.de/t2/trunk/package/base/linux/hda-realtek.patch
> >> 
> >> This affects more devices (e.g. Dell XPS 13, ThinkPads) any maybe many more which I do not have at hand.
> >> 
> >> Further guidance how to proceed with this issue to get it fixed upstream is welcome.
> > 
> > As mentioned, a better way is to define the preferred mapping table.
> > Take a look at alc274_fixup_bind_dacs() as an example
> 
> Did you had a chance to look at the log I uploaded to get an idea if it is possible to improve this auto parser to figure out the connection?

Did you take a look at the function?  It's pretty straightforward, you
can specify the mapping you'd need there.


Takashi

> 
> 	René
> 
> > Takashi
> > 
> >> 
> >> 	René
> >> 
> >> On 06 Mar 2018, at 16:07, René Rebe <rene at exactcode.de> wrote:
> >> 
> >>> Hi Takashi,
> >>> 
> >>> On 03/05/2018 12:55 PM, Takashi Iwai wrote:
> >>>> On Sat, 03 Mar 2018 13:06:49 +0100,
> >>>> René Rebe wrote:
> >>>>> 
> >>>>> Hi all,
> >>>>> 
> >>>>> testing some new laptops, I noticed the headphone frequency response was lacking
> >>>>> bass. First I noticed this in the Lenovo T470s, and later I found this also be the case
> >>>>> on Surface Pro 2 and 3. The Dell XPS13 may also be affected, but I had to return it
> >>>>> before I found out the solution on the other machines:
> >>>>> 
> >>>>> 	https://www.youtube.com/watch?v=a1YkPtfC4LI
> >>>>> 
> >>>>> I had not yet sent the patch because a) I was too busy and b) I wanted to review this further.
> >>>>> 
> >>>>> As the other day I got a Lenovo ideapad 720s to test with exactly the same issue, here is the
> >>>>> current hacked patch:
> >>>>> 
> >>>>> 	https://svn.exactcode.de/t2/trunk/package/base/linux/surface-audio.patch
> >>>>> 
> >>>>> However, given that all newer realtek codecs that came on my desk are affected,
> >>>>> maybe there is something wrong with the hda_auto_parser.c - I did not yet fully grasp
> >>>>> all the logic of that.
> >>>>> 
> >>>>> As you can see in the patch and video (…) the problem is the signal routing of NID 0x15
> >>>>> or 0x21 (depending whether it is an older, or newer codec). This is the headphone out,
> >>>>> and as far as I can see the auto_parser assigned the index 0 pcm output (NID 0x0c)
> >>>>> which result in this filtered frequency response, likely intended for the laptop’s speakers?
> >>>>> Using the next NID (I guess that was 0xd?) results in a full frequency response and at
> >>>>> least to my ears is immediately hearable and obvious.
> >>>>> 
> >>>>> Without this fixed routing the headphone sounds like a PC speaker in a coke can.
> >>>>> 
> >>>>> So the question for the authors and HDA experts: Can this be fixed in the auto_parser,
> >>>>> or is my patch (which btw. has to small unrelated cleanups) modulo potentially some
> >>>>> renaming of the enum and function, now that more than the Surface is affected, the
> >>>>> way to go? If this can be fixed more generally I would be happy to hear!
> >>>> Could you give the output of alsa-info.sh?  We need to check the
> >>>> details of the codec topology.
> >>> 
> >>> To avoid sending the huge output to the list, I pressed the upload button, and it gave me this Url:
> >>> 
> >>> 
> >>> 	http://www.alsa-project.org/db/?f=c68cad9c06aa999f017f1e43b52448d778d2903f
> >>> 
> >>> This is with the linked patch, if you want to see it without the change, I need to re-build my kernel again :-/
> >>> 
> >>>> In general, the right approach is to fix at parsing the routing, not
> >>>> fiddling with the codec routing dynamically at initialization.
> >>>> Currently the easy fix would be to provide the fixed DAC connection
> >>>> list.  Maybe we can enhance the generic parser to receive some hints
> >>>> for DAC selection.  The routes are determined by calculating "badness"
> >>>> values per route, so in theory, we can give some badness values
> >>>> depending on the target pin type (headphone, speaker, etc).
> >>> 
> >>> Let me know if I should try some alternative solution, ...
> >>> 
> >>> 	René
> >>> 
> >>> -- 
> >>> René Rebe, ExactCODE GmbH, Lietzenburger Str. 42, DE-10789 Berlin
> >>> https://exactcode.com | https://t2sde.org | https://rene.rebe.de
> >> 
> >> -- 
> >> ExactCODE GmbH, Lietzenburger Str. 42, DE-10789 Berlin
> >> DE Legal: Amtsgericht Berlin (Charlottenburg) HRB 105123B, Tax-ID#: DE251602478
> >> Managing Director: René Rebe
> >> http://exactcode.com | http://exactscan.com | http://ocrkit.com | http://t2-project.org | http://rene.rebe.de
> >> 
> 
> -- 
>  ExactCODE GmbH, Lietzenburger Str. 42, DE-10789 Berlin
>  DE Legal: Amtsgericht Berlin (Charlottenburg) HRB 105123B, Tax-ID#: DE251602478
>  Managing Director: René Rebe
>  http://exactcode.com | http://exactscan.com | http://ocrkit.com | http://t2-project.org | http://rene.rebe.de
>