"Sample format non available" with snd-usb-audio [solved]

[vputz]

Okay, annoying problem. I've got an Audigy 2 in my computer (card 0) and a Plantronics headset (card 1). I can see both of them in /proc/asound/devices, and alsamixer can configure them and everything looks right. Playing something using card 0 presumably works (no errors, but I have no speakers right now), but playing anything on the headseat dies. using "aplay -D hw:0,0" works fine, in other words, but "aplay -D hw:1,0" gives me

aplay: set_params:900: Sample format non available

The odd thing is that with an earlier kernel it worked semi-fine (unplug/replug, restart alsa, no worries).

Now, I figured it might be fixable by making an .asoundrc with the line "format (something)". But that's not the case. With "format S16_LE" it gives the same error, although with any other format (ok, I just tried "S32_LE" and "S24_LE") it gives

aplay: set_params:878: Broken configuration for this PCM: no configurations available

Cool. It's a Plantronics USB headset. I'm stumped. Tried searching but just got confused. Save me!

[absoluteflatness]

"cat /proc/asound/card1/stream0", or "lsusb -v" should be able to tell you your device's accepted sample rates.

You could also try doing "aplay -D plughw:1,0". That should do any necessary sample conversion for you, hopefully.

[vputz]

Hm.

$ cat /proc/asound/card1/stream0
Plantronics Plantronics Headset at usb-0000:00:02.1-1.3, full speed : USB Audio

Playback:
Status: Stop
Interface 1
Altset 1
Format: 0x2
Channels: 1
Endpoint: 1 OUT (ADAPTIVE)
Rates: 6400 - 48000 (continuous)
Interface 1
Altset 2
Format: 0x2
Channels: 2
Endpoint: 1 OUT (ADAPTIVE)
Rates: 6400 - 48000 (continuous)

Capture:
Status: Stop
Interface 2
Altset 1
Format: 0x0
Channels: 1
Endpoint: 4 IN (SYNC)
Rates: 6400 - 48000 (continuous)
Interface 2
Altset 2
Format: 0x2
Channels: 1
Endpoint: 4 IN (SYNC)
Rates: 6400 - 48000 (continuous)
Interface 2
Altset 3
Format: 0x2
Channels: 2
Endpoint: 4 IN (SYNC)
Rates: 6400 - 48000 (continuous)

$ aplay -D plughw:1,0 a_sound_file.mp3
Playing raw data 'a_sound_file.mp3' : Unsigned 8 bit, Rate 8000 Hz, Mono
aplay: set_params:961: 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: 1000

I then tried an .asoundrc with rate 44100 to no avail. I'm sure there's something obvious I'm missing, but Alsa's quirky enough that I'm not sure what it is.

[vputz]

Found the missing bit. Playing USB audio through a hub seems to require a kernel option I wasn't aware of--I believe it was CONFIG_USB_EHCI_SPLIT_ISO=y. Added that and it seems to be happy.