BlueZ

It seems Joao Paulo have been pretty busy lately working on GSoC project: bluetooth audio support for PulseAudio, and here is a preview of his work:

As you can see PulseAudio are now able to handle Bluetooth audio devices (A2DP and HSP). There are still some missing features that we want to add, a proper wizard on BlueZ to pair/connect those devices and some bugs which we should take care before releasing the code so don’t expect it to work flawless.

To test it run:

pulseaudio -L “module-bt-device name=<name> addr=xx:xx:xx:xx:xx:xx profile=<a2dp,hsp> rate=<8000-48000> channels=<1,2>”

kudos to Joao Paulo and Lennart

The new btusb driver gets finally SCO over USB support. This allows the usage of mono headsets for VoIP calls.

patch-2.6.26-mh3.gz

It seems that commercial stack manufactures like to spread FUD (Fear, uncertainty and doubt) about BlueZ and its qualification status. Trying to eliminate the open source competition by telling customers that BlueZ can’t be qualified is just plain bad business practice and these companies are lying to you.

The truth is that BlueZ has been qualified according to the Bluetooth PRD 2.0 (and later) and has been used successful in products. The most prominent example is the Nokia N810 Internet tablet. It is based on the Maemo platform which includes BlueZ as one of its core components. If you don’t believe me, check the official qualification record by yourself.

To help qualifying BlueZ based products we split the qualification into components for the host stack (GAP, L2CAP, RFCOMM and SDP) and profile stack. Companies like Nokia, ACCESS, TomTom and others have sponsored the qualification of BlueZ components that can be re-used by others.

Current known qualification records can be found at the BlueZ qualification page and it is expected that are more products out there are using BlueZ and have successfully passed the Bluetooth qualification.

If there exist any questions when it comes to BlueZ qualification, feel free to mail me. You find my email address in the source code.

For Bluetooth USB devices, the current driver is called hci_usb. However the new btusb driver is suppose to take over. This update now makes sure that all quirks are also present in this new driver.

patch-2.6.26-mh2.gz

The missing piece in the btusb driver is the full SCO support. Oliver Neukum is working on this and I hope we will see an update soon.

The Bluetooth 2.1 specification has been released over a year ago and so far no Bluetooth 2.1 device made it to market. However in the past months a couple of devices with Bluetooth 2.1 capable chips showed up. The only problem is that even with these chips built in, the host stacks on these devices are still only implementing the Bluetooth 2.0 specification. Examples of such devices are:

• Apple iPhone 3G
• Apple MacBook, MacBook Pro and MacBook Air
• Asus EeePC 901

So in theory all of these devices could support Simple Pairing and Extended Inquiry, but for some reason both companies decided to go the easy way. And I guess there are even more out there since I had a Symbian based Samsung phone in my hands with a Bluetooth 2.1 chips, but no 2.1 features enabled.

All big host stack vendors like Microsoft, Apple, Broadcom and Symbian are working on Simple Pairing support, but only BlueZ has put it out there for public consumption. Seems like everybody is waiting for the others to go first.

So I am most disappointed with Apple here since neither their iPhone 3G nor their new MacBooks make use of the possibilities that their hardware offers.

BD Address:  00:21:E9:xx:xx:xx
Device Name: Marcel’s iPhone 3G
LMP Version: 2.1 (0×4) LMP Subversion: 0×12e9
Manufacturer: Cambridge Silicon Radio (10)
Features: 0xff 0xff 0×8f 0xfe 0×9b 0xff 0×59 0×83

And it is not about which company provided the Bluetooth chip since Apple clearly buys chips from CSR and Broadcom. While on older MacBooks and other Apple machines clearly CSR dominated, they now also go with Broadcom like they have done for their keyboard and mouse products.

BD Address:  00:21:E9:xx:xx:xx
Device Name: Marcel’s MacBook Pro
LMP Version: 2.1 (0×4) LMP Subversion: 0×2187
Manufacturer: Broadcom Corporation (15)
Features: 0xff 0xff 0×8f 0xfe 0×9b 0xff 0×71 0×83

Both iPhones still have a CSR chip in it. The original comes with a 2.0 chip and the 3G version with the 2.1 version of it.

When the Bluetooth 1.2 specification was development, Apple was the first ones to add support for Adaptive Frequency Hopping (AFH) to their products and also provided firmware updates for the chips they used. I expected Apple to push forward with Simple Pairing support, but now I think it is unlikely to happen soon.

BD Address:  00:15:AF:xx:xx:xx
Device Name: Marcel’s EeePC 901
LMP Version: 2.1 (0×4) LMP Subversion: 0×420e
Manufacturer: Broadcom Corporation (15)
Features: 0xff 0xff 0×8f 0xfe 0×9b 0xff 0×79 0×83

The EeePC 901 comes with Windows XP per-installed at the moment. Installing Linux with a 2.6.27 kernel and BlueZ 4.0 on it would make it the first product with Simple Pairing and Extended Inquiry support. So happy hacking.

It is now official that bluez-libs-3.36 and bluez-utils-3.36 were the last releases in the BlueZ 3.x series. Both repository are now in maintenance mode and only important security fixes will justify another release from the 3.x branch.

For the BlueZ 4.x series the repositories have been moved from SourceForge.net over to kernel.org and we are now using GIT for revision control. Also bluez-libs and bluez-utils have been merged back together into one common bluez.git repository.

The 4.x series brings two important changes. The first one is that the eglib support has been completely removed. This means that GLib now becomes a hard depedency. The second one is that we removed the old D-Bus and now fully concentrate on improving the new API and making the code simpler, cleaner and easy to read and understand.

We haven’t had time to move bluez-gnome over to the new D-Bus API. So if you wanna try bluez-4.x be warned that this will break.

The merge window for the Linux 2.6.27 kernel opened just after the official release of 2.6.26 and on the Bluetooth side we have a big update pending to be merged. Most changes are security enhancements and full support for Simple Pairing from the Bluetooth 2.1 specification.

After an absence of two kernel release, I started to produce my -mh kernel patches again. And since we are moving a lot of the infrastructure to kernel.org these patches have their new home their, too. So have fun with it.

patch-2.6.26-mh1.gz

During the BlueZ developer meeting in Helsinki a month ago we talked with Lennart Poettering about the native integration of A2DP and Headset support with PulseAudio. He requested some enhancements to our Bluetooth support in the Linux kernel for a better synchronization of the audio stream.

• Support for SO_TIMESTAMP and/or SIOCGSTAMP/SIOCGSTAMPNS
• Support for TIOCOUTQ and TIOCINQ ioctls
• Support for retrieving the remote clock value

The current GIT tree is based on the 2.6.26-rc8 kernel release and contains support for the first two items on his list.

Adding the possibility to retrieve the remote clock value has not been implemented yet. The technical part is not really complicated, but I am not sure on how to present this information to the user-space.

This patch set also contains an update to the Simple Pairing support and a fix for the driver model integration of the low-level connections.