USB audio device on Raspberry Pi - link_elf: symbol isa_dmastatus undefined

[Hans Petter Selasky]

On 04/30/14 11:14, Scott Aitken wrote:
> Hi again,
>
> good call on the kernel recompile.  I added sound and uaudio to the kernel
> and low and behold things improved:
>
>
> root at raspberry-pi:/mnt # dmesg
> ...
> ugen0.4: <danyigao audio equipment> at usbus0
> uaudio0: <danyigao audio equipment DARED AUDIO, class 0/0, rev 2.00/1.00, addr 4> on usbus0
> uaudio0: Play: 96000 Hz, 2 ch, 24-bit S-LE PCM format, 2x8ms buffer.
> uaudio0: Play: 48000 Hz, 2 ch, 24-bit S-LE PCM format, 2x8ms buffer.
> uaudio0: Play: 44100 Hz, 2 ch, 24-bit S-LE PCM format, 2x8ms buffer.
> uaudio0: No recording.
> uaudio0: No MIDI sequencer.
> pcm0: <USB audio> on uaudio0
>
> However, when I play a file to /dev/dsp, I get an error in dmesg:
>
> root at raspberry-pi:/mnt # cat /bin/ls > /dev/dsp
> cat: stdout: Invalid argument
> root at raspberry-pi:/mnt # dmesg
> ...
> pcm0: chn_write(): pcm0:virtual:dsp0.vp0: play interrupt timeout, channel dead
>

Hi,

In the "sys/dev/usb/controller/dwc_otg.c" driver the isochronous method 
which your audio device is using, is not implemented, because it causes 
excessive interrupts. So the USB transfer simply times out.

--HPS