[PATCH v2 0/2] Fix Lenovo ThinkPad X1 Carbon 7th gen bass volume

[Benjamin Poirier]

This is an updated version of the patchset to fix the low output volume on
the Lenovo ThinkPad X1 Carbon 7th gen. With these patches, the volume
output with the Linux driver matches the one with the Windows driver.
Volume control is effective and headphone output is unaffected.

Multiple users of this machine have reported a low output volume [1] when
using a kernel with commit d2cd795c4ece ("ALSA: hda - fixup for the bass
speaker on Lenovo Carbon X1 7th gen"). Many have tried these patches or a
similar workaround using `hda-verb` and prefer this configuration[2].

As noted in patch 2, the changes also depend on an associated alsa-ucm-conf
change.

[1]
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3227516
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3240090
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3296637
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3304699
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3343871
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3349803
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3361380
...

[2]
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3343252
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3344118
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3345062
https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3345107
...

Changes:

v1
==
https://lore.kernel.org/alsa-devel/20200211055651.4405-1-benjamin.poirier@gmail.com/

v2
==
* patch 1
Shortened log

* patch 2
Change log to replace experimental observations by information from diagram
posted on kernel.org bugzilla.
Select exactly the desired connection for node 0x17 (bass speakers) instead of
reusing alc295_fixup_disable_dac3().
Control node 0x21 (headphones) connection to avoid the volume "wobble"
effect described in the log.
Include SET_CONNECT_SEL command in fixup since it is not done by the hda
core.
Rename one control to reflect its new function and to use as a condition in
the ucm config.


Benjamin Poirier (2):
  ALSA: hda/realtek - Fix Lenovo Thinkpad X1 Carbon 7th quirk subdevice
    id
  ALSA: hda/realtek - Replace Lenovo Thinkpad X1 Carbon 7th quirk

 sound/pci/hda/patch_realtek.c | 57 ++++++++++++++++++++++++++++++++---
 1 file changed, 52 insertions(+), 5 deletions(-)

-- 
2.27.0