hmmm. my associate needs a USB sound thing in his stack... its always worked before, but when I brought him up on a new system with 6.7, the device is recognized....
usb 1-1: New USB device found, idVendor=08bb, idProduct=2704 usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-1: Product: USB Audio DAC usb 1-1: Manufacturer: Burr-Brown from TI usb 1-1: configuration #1 chosen from 1 choice usb 1-1: ctrl urb status -75 received input: Burr-Brown from TI USB Audio DAC as /devices/pci0000:00/0000:00:01.2/usb1/1-1/1-1:1.2/input/input3 generic-usb 0003:08BB:2704.0001: input,hidraw0: USB HID v1.00 Device [Burr-Brown from TI USB Audio DAC ] on usb-0000:00:01.2-1/input2
and it shows up as...
$ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: I82801AAICH [Intel 82801AA-ICH], device 0: Intel ICH [Intel 82801AA-ICH] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: DAC [USB Audio DAC], device 0: USB Audio [USB Audio] Subdevices: 1/1 Subdevice #0: subdevice #0
but when he tries to connect to it, like with this test command...
$ mpg123 -a hw:1,0 /audio/36790.mp3 Playing MPEG stream 1 of 1: 36790.mp3 ... [alsa.c:118] error: initialize_device(): cannot set hw params [audio.c:643] error: failed to open audio device [mpg123.c:547] error: failed to reset audio device: Broken pipe
and I noted some kernel errors in dmesg...
usb 1-1: cannot submit urb 0, error -22: internal error usb 1-1: cannot submit urb 0, error -22: internal error usb 1-1: cannot submit urb 0, error -22: internal error
reading a random forum thread found via googling that error suggested someone else had this problem with 6.7 and reverted. I was running
$ uname -a Linux kfat.com 2.6.32-573.7.1.el6.x86_64 #1 SMP Tue Sep 22 22:00:00 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
So, reverting to a older kernel fixed this, and it works fine.
$ uname -a Linux kfat.com 2.6.32-431.17.1.el6.x86_64 #1 SMP Wed May 7 23:32:49 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
(I had a 6.5 rpm handy).
any clues? Linux audio has always been a big black box to me.