linux-stable/Documentation/sound
Thomas Hebb f128090491 ALSA: doc: Document PC Beep Hidden Register on Realtek ALC256
This codec (among others) has a hidden set of audio routes, apparently
designed to allow PC Beep output without a mixer widget on the output
path, which are controlled by an undocumented Realtek vendor register.
The default configuration of these routes means that certain inputs
aren't accessible, necessitating driver control of the register.
However, Realtek has provided no documentation of the register, instead
opting to fix issues by providing magic numbers, most of which have been
at least somewhat erroneous. These magic numbers then get copied by
others into model-specific fixups, leading to a fragmented and buggy set
of configurations.

To get out of this situation, I've reverse engineered the register by
flipping bits and observing how the codec's behavior changes. This
commit documents my findings. It does not change any code.

Cc: stable@vger.kernel.org
Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Link: https://lore.kernel.org/r/bd69dfdeaf40ff31c4b7b797c829bb320031739c.1585584498.git.tommyhebb@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-31 10:51:45 +02:00
..
cards ALSA: multisound.sh: update module namespace 2018-06-26 17:45:16 +02:00
designs ALSA: pcm: add a documentation for tracepoints 2017-07-02 11:15:52 +02:00
hd-audio ALSA: doc: Document PC Beep Hidden Register on Realtek ALC256 2020-03-31 10:51:45 +02:00
kernel-api sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
soc ASoC: simple-card: Add support for codec2codec DAI links 2020-03-06 14:24:11 +00:00
alsa-configuration.rst ALSA: usb-audio: Update the documentation for the new delayed_register option 2020-03-26 10:49:21 +01:00
index.rst docs: index.rst: don't use genindex for pdf output 2019-07-31 13:31:16 -06:00