[alsa-devel] Alsa simultaneous use of usb-sound card - BW problem

[Burak METİN]

Hi,

I have 2 CM6571 usb sound cards.

In Ubuntu, i want to use these 2 cardds simultaneously. I open 2 terminals,
and arecord -D plughw:1,0 | aplay -D plughw:1,0 in one terminal, it works
well. but when i type arecord -D plughw:2,0 | aplay -D plughw:2,0 in
another terminal, in second terminal, it says

Recording WAVE 'stdin' : Unsigned 8 bit, Rate 8000 Hz, Mono
arecord: xrun:1552: Playing WAVE 'stdin' : read/write error, state =
PREPAREDUnsigned 8 bit,
Rate 8000 Hz, Mono
aplay: set_params:1297: Unable to install hw params:
ACCESS:  RW_INTERLEAVED
FORMAT:  U8
SUBFORMAT:  STD
SAMPLE_BITS: 8
FRAME_BITS: 8
CHANNELS: 1
RATE: 8000
PERIOD_TIME: 125000
PERIOD_SIZE: 1000
PERIOD_BYTES: 1000
PERIODS: 4
BUFFER_TIME: 500000
BUFFER_SIZE: 4000
BUFFER_BYTES: 4000
TICK_TIME: 0

When ı dmesg, it says:

[ 5418.913160] retire_playback_urb: 1673 callbacks suppressed
[ 5419.253436] cannot submit urb 0, error -28: not enough bandwidth
[ 5419.254887] cannot submit urb 0, error -28: not enough bandwidth

I think it is about the usb driver in alsa, any ideas?