[alsa-devel] UAC2 clock selector for AudioBox 1818VSL

[louis at museresearch.com]

Hi Daniel,
  I've applied the patch, and this is the output. When I call it with
value 0, nothing happens. When I set it to higher values, it looks like
some (attempted?) communication happens with the device. I added another
debug line which spits out the value_set parameter also.

[root at TestName linux-3.4.5-2.muse1.rt13.2.fc15.x86_64]# amixer -c 2 cset
numid=5,iface=MIXER,name='AudioBox 1818 VSL Clock Selector' 0

numid=5,iface=MIXER,name='AudioBox 1818 VSL Clock Selector'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'AudioBox 1818 VSL Internal Clock'
  ; Item #1 'AudioBox 1818 VSL S/PDIF Clock'
  ; Item #2 'AudioBox 1818 VSL ADAT Clock'
  : values=0

[root at TestName linux-3.4.5-2.muse1.rt13.2.fc15.x86_64]# amixer -c 2 cset
numid=5,iface=MIXER,name='AudioBox 1818 VSL Clock Selector' 1

numid=5,iface=MIXER,name='AudioBox 1818 VSL Clock Selector'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'AudioBox 1818 VSL Internal Clock'
  ; Item #1 'AudioBox 1818 VSL S/PDIF Clock'
  ; Item #2 'AudioBox 1818 VSL ADAT Clock'
  : values=0
Sep 10 09:45:16 TestName kernel: [ 4486.890466] ALSA sound/usb/mixer.c:444
Called with value_set=2
Sep 10 09:45:16 TestName kernel: [ 4486.890566] ALSA sound/usb/mixer.c:476
 DEBUG: snd_usb_mixer_set_ctl_value(): request 00000001 requesttype
00000021, value 0100, index 2800, size 2

[root at TestName linux-3.4.5-2.muse1.rt13.2.fc15.x86_64]# amixer -c 2 cset
numid=5,iface=MIXER,name='AudioBox 1818 VSL Clock Selector' 2

numid=5,iface=MIXER,name='AudioBox 1818 VSL Clock Selector'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'AudioBox 1818 VSL Internal Clock'
  ; Item #1 'AudioBox 1818 VSL S/PDIF Clock'
  ; Item #2 'AudioBox 1818 VSL ADAT Clock'
  : values=0
Sep 10 09:45:20 TestName kernel: [ 4490.090214] ALSA sound/usb/mixer.c:444
Called with value_set=3
Sep 10 09:45:20 TestName kernel: [ 4490.090256] ALSA sound/usb/mixer.c:476
 DEBUG: snd_usb_mixer_set_ctl_value(): request 00000001 requesttype
00000021, value 0100, index 2800, size 2

Louis


>> There are some other details that may be relevant, but I didn't want to
>> make my initial post too long/confusing because these extra details may
>> end up just being a red herring: Each mixer element name (as seen in
>> amixer) is prefixed with "AudioBox 1818 VSL Clock Selector" even if it
>> is
>> not a clock selector.
>
> That strange but I believe not related. We should still fix that :)
>
>> I am confident though that the control I've been
>> playing with is the clock selector because it lists the different clock
>> types as options. I also see this when I plug the device in or load the
>> ALSA driver:
>>
>> ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue =
>> 0x201, wIndex = 0xa00, type = 4
>> ALSA sound/usb/mixer.c:846 10:0: cannot get min/max values for control 2
>> (id 10)
>> ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue =
>> 0x200, wIndex = 0xa00, type = 4
>> ALSA sound/usb/mixer.c:846 10:0: cannot get min/max values for control 2
>> (id 10)
>> ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue =
>> 0x201, wIndex = 0xb00, type = 4
>> ALSA sound/usb/mixer.c:846 11:0: cannot get min/max values for control 2
>> (id 11)
>> ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue =
>> 0x200, wIndex = 0xb00, type = 4
>> ALSA sound/usb/mixer.c:846 11:0: cannot get min/max values for control 2
>> (id 11)
>
> Do you see any messages when you try to set the clock selector with
> amixer?
>
> If you're running a recent kernel, try the following patch. That will
> produce log messages for each mixer related control packet that is sent
> out to the device.
>
>
> Thanks,
> Daniel
>
>
>
>