[LAU] Sound Devices USBPre2, UAC2 status

[Hans Wilmers]

On 01/10/2013 10:30 PM, shal at free.fr wrote:
>
>> De: "Hans Wilmers" <hanswil at notam02.no>
>> No luck with this either - fastest one I get is 48000. This
>> corresponds
>> to the output of lsusb, which does not list samplerates over 48000
>> for
>> this device.
>
>
> I have tried different kernel, 3.2 to 3.7.1, vanilla or ubuntu kernel.
>
> The lsusb does not means that you are limited to 48000.
>
> The lsusb provides the "devices descriptor" and a devices descriptors has one or more "configuration descriptor". The kernel chooses one of the "configuration descriptor".
> In your device descriptor (provided directly by the device) there is two possibles configuration descriptons (the bNumConfigurations=2). The first one corresponds to the UAC1 mode in high-speed (this is my one configuration) and so limited to 48000. The second one is the UAC2 mode (the expected mode).
>
> Perhaps the kernel choose the fist good one, so UAC1  .
>
> Can you send the result of  cat /proc/asound/USBPre2/stream0  ?
>

Yes, see below.

/ Hans


--------------- /proc/asound/USBPre2/stream0 -------------

Sound Devices USBPre2 at usb-0000:00:1a.0-1.2, high speed : USB Audio

Playback:
   Status: Stop
   Interface 1
     Altset 1
     Format: S16_LE
     Channels: 2
     Endpoint: 6 OUT (ASYNC)
     Rates: 8000, 16000, 24000, 32000, 44100, 48000
     Data packet interval: 1000 us
   Interface 1
     Altset 2
     Format: S24_3LE
     Channels: 2
     Endpoint: 6 OUT (ASYNC)
     Rates: 8000, 16000, 24000, 32000, 44100, 48000
     Data packet interval: 1000 us

Capture:
   Status: Stop
   Interface 2
     Altset 1
     Format: S16_LE
     Channels: 2
     Endpoint: 5 IN (ASYNC)
     Rates: 8000, 16000, 24000, 32000, 44100, 48000
     Data packet interval: 1000 us
   Interface 2
     Altset 2
     Format: S24_3LE
     Channels: 2
     Endpoint: 5 IN (ASYNC)
     Rates: 8000, 16000, 24000, 32000, 44100, 48000
     Data packet interval: 1000 us

--------------------------------------------------------------