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?