bluetooth 2.0 is extremely slow

[Bastien Nocera]

On Tue, 2008-04-01 at 11:11 -0500, Mike Cronenworth wrote:
> Hi all,
> 
> I've lived with slow transfer speeds long enough. Ever since I purchased
> an ASUS Bluetooth 2.0+EDR USB adapter it has always taken *minutes*
> instead of *seconds* to transfer files from my cell phone to my computer
> and vice versa.
> 
> Fedora 8, latest updates.
> Nokia N95-1, latest firmware.
> 
> Both are Bluetooth 2.0+EDR devices.
> 
> It took *40 seconds* to transfer a 1 megabyte picture. I timed this with
> 'watch -n 1 date' for grins, so I can't give you nanosecond numbers, but
> even a rough estimate shows that transfer speeds are *abysmal* and need
> to be addressed. Ideally it should be taking less than 10 seconds to
> transfer the same image file on a true 2.0+EDR setup. I have two
> different computers with two of the same Asus adapter. Same speeds.

That certainly doesn't rule out a bug in the dongle's firmware for
example.

> I saw someone fixed this by forcing larger MTUs.
> http://lists.freebsd.org/pipermail/...ary/000847.html
> <http://lists.freebsd.org/pipermail/freebsd-bluetooth/2007-January/000847.html>
> 
> Before modifying the OpenOBEX sources, I posted a message on their
> board, but I haven't heard anything yet. Does anyone have any experience
> with this?

OpenObex upstream is pretty much dead(-ish). Let's call it maintenance
mode.

> I have tried the fedora-list without an answer. Also, the OpenOBEX 
> developers are silent on this. Is this because no one has a 2.0 adapter 
> and 2.0 device?

Probably not, one of the upstream for OpenObex is Marcel Holtmann, and
he certainly has more Bluetooth 2.0 devices than you or I.

Test the patch, tell us if it works, and mail the bluez-users list about
it. There's also ACL and SCO MTUs to take in consideration, and I would
guess the bug is more likely to be there (in the kernel, in the firmware
of your dongle, or the firmware of your phone) than solely in OpenObex.

Cheers