[alsa-devel] snd-usb-audio issues??
tiwai at suse.de
Mon Apr 14 15:43:34 CEST 2014
At Mon, 14 Apr 2014 15:26:45 +0200,
Clemens Ladisch wrote:
> Richard Storer wrote:
> > bTerminalID 4
> > wTerminalType 0x0603 Line Connector
> > bDescriptorSubtype 6 (FEATURE_UNIT)
> > bUnitID 5
> > bSourceID 4
> > bmaControls( 0) 0x02
> > Volume Control
> That single capture mixer control controls the line input.
> (I don't know why it's labelled as "Mic", or how the device
> switches between mic and line signal levels.)
It comes from live24ext_map in mixer_maps.c, introduced via commit
69b1f1e8337fc94a7ea0730588960e82676dc2dc, reading below:
Author: Timofei Bondarenko <tim at ipi.ac.ru>
Date: Tue Oct 30 15:28:14 2007 +0100
[ALSA] usb-audio - SB Live24-External better handling
This patch improves support for 'SB Live 24-bit Extarnal' USB card.
1) This card can go into muted state when a headphones connected or
disconnected. So notify mixer about changes in headphone jack.
2) Add LED controls and procfs support just as in similar Audigy 2 NX card.
3) Rename 'PCM Capture' conrol to 'Mic Capture' to reflect reality:
the card may adjust microphone input level only.
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