Re: [alsa-devel] snd_usb_audio - siberia elite prism soundcard issues

13 Mar 2015


      2015-03-12 2:10 GMT+01:00 Raymond Yau superquad.vortex2@gmail.com:
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> > >
> > > > amixer: Control hw:2 element read error: Invalid argument
> > > > usb 1-1.3: 10:0: cannot get min/max values for control 3
(id 10)
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> > > > usb 1-1.3: 2:1: cannot get freq at ep 0x1
numid=5,iface=MIXER,name='PCM Volume' ;
type=INTEGER,access=rw------,values=2,min=0,max=1,step=0 amixer: Control
hw:2 element read error: Invalid argument
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numid=6,iface=MIXER,name='PCM Volume',index=1 ;
type=INTEGER,access=rw------,values=1,min=0,max=1,step=0 amixer: Control
hw:2 element read error: Invalid argument
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numid=7,iface=MIXER,name='PCM Volume',index=2 ;
type=INTEGER,access=rw------,values=1,min=0,max=1,step=0 amixer: Control
hw:2 element read error: Invalid argument
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numid=8,iface=MIXER,name='PCM Volume',index=3 ;
type=INTEGER,access=rw------,values=1,min=0,max=1,step=0 amixer: Control
hw:2 element read error: Invalid argument
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numid=9,iface=MIXER,name='PCM Volume',index=4 ;
type=INTEGER,access=rw------,values=1,min=0,max=1,step=0 amixer: Control
hw:2 element read error: Invalid argument
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  AudioControl Interface Descriptor:
    bLength                13
    bDescriptorType        36
    bDescriptorSubtype      4 (MIXER_UNIT)
  Warning: Descriptor too short
    bUnitID                10
    bNrInPins               2
    baSourceID( 0)          9
    baSourceID( 1)          1
    bNrChannels            8
    wChannelConfig     0x063f
      Left Front (L)
      Right Front (R)
      Center Front (C)
      Low Freqency Enhancement (LFE)
      Left Surround (LS)
      Right Surround (RS)
      Side Left (SL)
      Side Right (SR)
    iChannelNames           0
    bmControls         0x00
    bmControls         0x00
    iMixer                 33 (error)

Refer to usb audio specification 1.0
Table 4-5: Mixer Unit Descriptor
bLength = 10 +  p +  N = 14
Number of Input Pins of this Unit: p
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    bNrInPins               2

The ID of the Unit or Terminal to which the first and second Input Pins of
this Mixer Unit is connected.
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    baSourceID( 0)          9

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    baSourceID( 1)          1

Number of logical output channels in the Mixer’s output audio channel
cluster.
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    bNrChannels            8

Describes the spatial location of the logical channels.
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    wChannelConfig     0x063f
      Left Front (L)
      Right Front (R)
      Center Front (C)
      Low Freqency Enhancement (LFE)
      Left Surround (LS)
      Right Surround (RS)
      Side Left (SL)
      Side Right (SR)

Bit map indicating which mixing Controls are programmable.
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    bmControls         0x00
    bmControls         0x00

The Mixer Unit Descriptor reports which Controls are programmable in the
bmControls bitmap field. This bitmap must be interpreted as a
two-dimensional bit array that has a row for each logical input channel and
a column for each logical output channel. If a bit at position [u, v] is
set, this means that the Mixer Unit contains a programmable mixing Control
that connects input channel u to output channel v. If bit [u, v] is clear,
this indicates that the connection between input channel u and output
channel v is non-programmable. Its fixed value can be retrieved through the
appropriate request. The valid range for u is from one to n. The valid
range for v is from one to m.
The bmControls field stores the bit array row after row where the MSb of
the first byte corresponds to the connection between input channel 1 and
output channel 1. If (n x m) is not an integer multiple of 8, the bit array
is padded with zeros until an integer number of bytes is occupied.
The number of bytes used to store the bit array, N, can be calculated as
follows:
IF ((n x m) MOD 8) <> 0 THEN
N = ((n x m) DIV 8) + 1
ELSE
N = ((n x m) DIV 8)
Index of a string descriptor, describing the name of the first logical
channel.
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    iChannelNames           0

Index of a string descriptor, describing the Mixer Unit.
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    iMixer                 33

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if (check_matrix_bitmap(c, ich, och, num_outs)) {
ich_has_controls = 1;
break;
}
}
This mean value returned by check_matrix_bitmap() is incorrect as
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    bmControls         0x00
    bmControls         0x00

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if (ich_has_controls)
build_mixer_unit_ctl(state, desc, pin, ich,
     unitid, &iterm);
}
}
return 0;
}
In case this can be of any useful info, in the form of unknown controls
reported by the lsusb output, manufacturer software in other OS has
controls for:
* dolby surround activation (off and on).
* microphone input volume (which works fine now) in snd_usb_audio
* microphone input "compression" (supposedly to keep input within certain
non distorting levels)
* input noise reduction (off and on too)
* micro retro feedback volume
* equalizer.
Thanks for your time.
-- 
*Daniel Ferradal*