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Takashi Iwai d074d9d52f ALSA: hda/realtek - Improved routing for Thinkpad X1 7th/8th Gen 
commit 6a6660d049 upstream.

There've been quite a few regression reports about the lowered volume
(reduced to ca 65% from the previous level) on Lenovo Thinkpad X1
after the commit d2cd795c4e ("ALSA: hda - fixup for the bass speaker
on Lenovo Carbon X1 7th gen").  Although the commit itself does the
right thing from HD-audio POV in order to have a volume control for
bass speakers, it seems that the machine has some secret recipe under
the hood.

Through experiments, Benjamin Poirier found out that the following
routing gives the best result:
* DAC1 (NID 0x02) -> Speaker pin (NID 0x14)
* DAC2 (NID 0x03) -> Shared by both Bass Speaker pin (NID 0x17) &
                     Headphone pin (0x21)
* DAC3 (NID 0x06) -> Unused

DAC1 seems to have some equalizer internally applied, and you'd get
again the output in a bad quality if you connect this to the
headphone pin.  Hence the headphone is connected to DAC2, which is now
shared with the bass speaker pin.  DAC3 has no volume amp, hence it's
not connected at all.

For achieving the routing above, this patch introduced a couple of
workarounds:

* The connection list of bass speaker pin (NID 0x17) is reduced not to
  include DAC3 (NID 0x06)
* Pass preferred_pairs array to specify the fixed connection

Here, both workarounds are needed because the generic parser prefers
the individual DAC assignment over others.

When the routing above is applied, the generic parser creates the two
volume controls "Front" and "Bass Speaker".  Since we have only two
DACs for three output pins, those are not fully controlling each
output individually, and it would confuse PulseAudio.  For avoiding
the pitfall, in this patch, we rename those volume controls to some
unique ones ("DAC1" and "DAC2").  Then PulseAudio ignore them and
concentrate only on the still good-working "Master" volume control.
If a user still wants to control each DAC volume, they can still
change manually via "DAC1" and "DAC2" volume controls.

Fixes: d2cd795c4e ("ALSA: hda - fixup for the bass speaker on Lenovo Carbon X1 7th gen")
Reported-by: Benjamin Poirier <benjamin.poirier@gmail.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Tested-by: Benjamin Poirier <benjamin.poirier@gmail.com>
Cc: <stable@vger.kernel.org>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207407#c10
BugLink: https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3214171
BugLink: https://gist.github.com/hamidzr/dd81e429dc86f4327ded7a2030e7d7d9#gistcomment-3276276
Link: https://lore/kernel.org/r/20200829112746.3118-1-benjamin.poirier@gmail.com
Link: https://lore.kernel.org/r/20200903083300.6333-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 		2020-09-09 19:12:33 +02:00
Documentation dt-bindings: mmc: tegra: Add tmclk for Tegra210 and later 2020-09-05 11:22:50 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch ARC: perf: don't bail setup if pct irq missing in device-tree 2020-09-09 19:12:30 +02:00
block blk-mq: order adding requests to hctx->dispatch and checking SCHED_RESTART 2020-09-03 11:27:01 +02:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto crypto: af_alg - Work around empty control messages without MSG_MORE 2020-09-03 11:27:05 +02:00
drivers Revert "net: dsa: microchip: set the correct number of ports" 2020-09-09 19:12:32 +02:00
fs btrfs: fix potential deadlock in the search ioctl 2020-09-09 19:12:31 +02:00
include include/linux/log2.h: add missing () around n in roundup_pow_of_two() 2020-09-09 19:12:29 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel kbuild: add variables for compression tools 2020-09-03 11:27:10 +02:00
lib test_kmod: avoid potential double free in trigger_config_run_type() 2020-08-21 13:05:37 +02:00
mm mm/vunmap: add cond_resched() in vunmap_pmd_range 2020-09-03 11:26:52 +02:00
net net: core: use listified Rx for GRO_NORMAL in napi_gro_receive() 2020-09-09 19:12:31 +02:00
samples bpf: Fix fds_example SIGSEGV error 2020-08-19 08:16:03 +02:00
scripts kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables 2020-09-03 11:27:10 +02:00
security Smack: prevent underflow in smk_set_cipso() 2020-08-19 08:16:16 +02:00
sound ALSA: hda/realtek - Improved routing for Thinkpad X1 7th/8th Gen 2020-09-09 19:12:33 +02:00
tools perf jevents: Fix suspicious code in fixregex() 2020-09-09 19:12:28 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set 2020-08-26 10:41:08 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
…
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
…
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.63 2020-09-05 11:22:51 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.