linux_dsm_epyc7002/sound
Takashi Iwai e7fdd52779 ALSA: hda - Implement loopback control switch for Realtek and other codecs
Many codecs, typically found on Realtek codecs, have the analog
loopback path merged to the secondary input of the middle of the
output paths.  Currently, we don't offer the dynamic switching in such
configuration but let each loopback path mute by itself.

This should work well in theory, but in reality, we often see that
such a dead loopback path causes some background noises even if all
the elements get muted.  Such a problem has been fixed by adding the
quirk accordingly to disable aamix, and it's the right fix, per se.
The only problem is that it's not so trivial to achieve it; user needs
to pass a hint string via patch module option or sysfs.

This patch gives a bit improvement on the situation: it adds "Loopback
Mixing" control element for such codecs like other codecs (e.g. IDT or
VIA codecs) with the individual loopback paths.  User can turn on/off
the loopback path simply via a mixer app.

For keeping the compatibility, the loopback is still enabled on these
codecs.  But user can try to turn it off if experiencing a suspicious
background or click noise on the fly, then build a static fixup later
once after the problem is addressed.

Other than the addition of the loopback enable/disablement control,
there should be no changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-12-08 17:00:42 +01:00
..
aoa ALSA: aoa-soundbus: Switch to dev_pm_ops 2015-08-05 16:47:47 +02:00
arm ASoC: pxa: pxa-pcm-lib: switch over to snd-soc-dmaengine-pcm 2015-09-30 23:21:16 +01:00
atmel ALSA: sound/atmel/ac97c.c: remove unused variable 2015-05-20 06:18:25 +02:00
core ALSA: compress: add support for 32bit calls in a 64bit kernel 2015-12-07 10:44:48 +01:00
drivers sound updates for 4.2-rc1 2015-06-25 17:15:18 -07:00
firewire ALSA: dice: fix detection of Loud devices 2015-11-14 17:50:57 +01:00
hda ALSA: hda - Add / fix kernel doc comments 2015-10-28 12:37:29 +01:00
i2c ALSA: i2c: constify snd_i2c_ops structures 2015-11-30 11:40:08 +01:00
isa ALSA: gus: use swap() in snd_ics_put_double() 2015-06-12 20:46:29 +02:00
mips ALSA: mips: let SND_SGI_O2 select SND_PCM 2015-06-15 13:21:58 +02:00
oss sound: oss/sb_audio: use swap() in sb_audio_close() 2015-06-12 20:46:29 +02:00
parisc
pci ALSA: hda - Implement loopback control switch for Realtek and other codecs 2015-12-08 17:00:42 +01:00
pcmcia
ppc ALSA: ppc: Add missing inclusion of linux/module.h 2015-08-25 14:13:36 +02:00
sh
soc ALSA: compress: Pass id string to snd_compress_new 2015-11-30 11:44:59 +01:00
sparc ALSA: sparc: amd7930: Fix module autoload for OF platform driver 2015-09-04 12:11:44 +02:00
spi
synth ALSA: synth: Fix conflicting OSS device registration on AWE32 2015-10-05 16:55:09 +02:00
usb ALSA: usx2y: fix inconsistent indenting on if statement 2015-12-02 18:03:24 +01:00
ac97_bus.c ASoC: Updates for v4.3 2015-08-31 16:25:22 +02:00
Kconfig
last.c
Makefile
sound_core.c sound: fix check for error condition of register_chrdev() 2015-11-07 11:14:30 +01:00
sound_firmware.c sound: sound_firmware: Fix invalid use of vfs_read() 2015-05-26 13:48:58 +02:00