# Is there still a btsco/snd_bt_sco module in 2.6.34

## hephooey

I am trying to make my bluetooth headset to work, I am following the bluetooth howto in the gentoo documentation, however I cannot find the "SCO (voice) support" module under "Bluetooth device drivers". Now I have everything else setup and the remote device(Plantronics Voyager 520) can connect without any problem. I also modified my asoundrc like this:

```

pcm.bluetooth {

   type bluetooth

   device xx:xx:xx:xx:xx:xx

   profile "auto"

}

ctl.bluetooth {

   type bluetooth

}

```

When I play a wav file with aplay -D bluetooth, I only hear 3 beep in my device and then some low white noise, and there are tons of error message like this in dmesg output:

```

btusb_send_frame: hci0 urb ffff88009c45ec00 submission failed

btusb_send_frame: hci0 urb ffff88009c45ea00 submission failed

btusb_send_frame: hci0 urb ffff88009c45e800 submission failed

btusb_send_frame: hci0 urb ffff88009c45e600 submission failed

btusb_send_frame: hci0 urb ffff88009c45ce00 submission failed

btusb_send_frame: hci0 urb ffff88009c45d000 submission failed

btusb_send_frame: hci0 urb ffff880021c50000 submission failed

btusb_send_frame: hci0 urb ffff880021c50200 submission failed

btusb_send_frame: hci0 urb ffff880021c50400 submission failed

btusb_send_frame: hci0 urb ffff880021c50600 submission failed

btusb_send_frame: hci0 urb ffff880021c50800 submission failed

btusb_send_frame: hci0 urb ffff880021c50a00 submission failed

btusb_send_frame: hci0 urb ffff880021c50c00 submission failed

```

All the howto about bluetooth headset I found said I need to load a module called btsco or snd_bt_sco to make the sound work. But I cannot find anything like that in 2.6.34, and no similar things bluez-4.71 either. Where should those code be, or they were replaced by something else?

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## ferrarif5

Hi,

Welcome to the fun that is bluetooth headphones in Linux  :Wink: 

Just today I finally got audio routed through my headphones (Sony DR-BT50) over bluetooth. Though I can't help you getting it working through ALSA alone, I can at least tell you how I got it working.

I installed Pulseaudio and used bluedevil(KDE Bluetooth connection app, Blueman is a similar GTK based app) to connect my headphones up. Just started up vlc (make sure you have pulseaudio flag enabled) and used pavucontrol to send the audio to my headphones (and enabled A2DP via pavucontrol) but left the rest the audio coming out my speakers.. am sure you could route it all through.

Am hoping to play around with it some more but am having issues with audio cutting out so I wouldn't say it worked flawlessly but maybe with just some tweaking  :Wink: 

Was just looking at my Bluetooth config in my kernel... am running gentoo-sources 2.6.34, under Networking Support --> Bluetooth Subsystem support --> I have SCO links support which is the module you are requesting... I've pretty much enabled everything except for RFCOMM TTY Support.

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## hephooey

Hi ferrarif5,

I also used bluedevil under kde, which seems work fine. My device only support SCO, no A2DP. I found some webpage said A2DP usually works better than SCO. I searched internet for several hours, a lot people have problem with the flooding

```
btusb_send_frame: hci0 urb ffff880063075400 submission failed

```

I tried 2.6.35 which gives me just noise too. I did not try to use pulseaudio however, its dependence on gnome-audio made me hesitated.

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## hephooey

I forgot to mention arecord does not work either, it seems there is not sound to record at all, I use -d 10 to record 10 seconds of sound, but arecord still runs forever until I kill it.

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## hephooey

Well, I managered to make the headset work on an T61 with gentoo. All the configurations are identical, and softwares are more or less the same version. The only differences is that machine is an 32bit system, and I am now using a pure 64bit setup. And the bluetootch chips are different. T61 has an older chip which need some fix in btsco, my new laptop (W510) use a new chip which seems no longer need the fix, but still the sound does not work. Guess I have to wait for the developers to figure out the quirks of the new chip.

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## hephooey

To conlude the story, I ended up get a bluetooth dongle on Amazon for $3, which works perfectly without any additional configuration. A interesting I noticed is that the dongle does not work when I use the usb3 port, if xhci_hcd is loaded the dongle will be recognized but I got the same error like the internal bt chip. If xhci_hcd is not loaded then the system will not recognize the dongle.

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## hephooey

I finally figured out almost everything, the trick is to select CONFIG_USB_EHCI_TT_NEWSCHED in the kernel, otherwise the usb will choke when too many devices are connected to a single bus. Now everything works like charm with the internal BT chip.

I also noticed a issue with skype+alsa+bluetooth, appearently skype prefer to have direct access to the bluetooth device, if you hide the bluetooth device as a slave of some plug device, you will again find the "btusb_send_frame: xxx xxx xxx submission failed" message flooding the log.

Hope this could help other people with similar troubles.

----------

