Creative Labs Sound Blaster Audigy cards (snd_emu10k1 driver) expose
mixer controls named 'PCM Front', 'PCM Rear', etc. in addition to the
more common 'Front', 'Rear', etc. The latter seem to be intended for
a stereo-to-all-speakers mirroring mode that we do not use, and have
no effect when we adjust them.
https://docs.kernel.org/sound/cards/audigy-mixer.html
We therefore define a custom mixer path for Audigy devices, using the
PCM mixer controls.
This has been tested on an Audigy 5/Rx. Based on a brief look at the
ALSA driver, I think all Audigy devices (vendor 0x1102, device 0x0004
or 0x0008) have the same PCM controls, making this change probably safe
for our existing Audigy udev rules.
Relevant kernel files:
sound/pci/emu10k1/emu10k1_main.c
sound/pci/emu10k1/emufx.c
include/sound/emu10k1.h
Fixes#2934
Motu M4 has four inputs (two line-in inputs, and two complete ones
with gain and XLR and whatnot), as well as four outputs (two monitor
pairs, and an unnaccounted headphone).
Sadly, like a few other interfaces, it wasn't being given an input
profile, since the matching code goes through default.conf testing
each config, and ends up selecting 'analog-surround-40', which does
not have input mapping. The inputs would fallback to 'multichannel-
input', which also doesn't have input paths.
Add input paths to all analog-surround-* mappings, and remove their
'direction=output' fields since they handle both out and in.
