Re: BlueZ pairing failure and kernel 2.6.24 crash

[Frederic Danis <frederic.danis@access-company.com>]

Hello Marcel,
> Hello Marcel,
>> Hi Frederic,
>>
>>> I am working with BlueZ 3.22, kernel 2.6.24 on ARM and found 2 
>>> problems :
>>>
>>> -  I am not able to pair with some phones (Nokia N70 and 
>>> sony-ericsson P800). After some investigations, I found that a "L2CAP 
>>> information request packet" is sent just after the ACL connection. 
>>> Both phones reply with "command rejected" error, then disconnect the 
>>> ACL link before BlueZ is able to finish the pairing (see attached 
>>> traces).
>>>
>>> - with some other phones (LG 990 Viewty and sony-ericsson T610), the 
>>> kernel crashes after pairing initiated by the phone is completed.
>>>
>>> For the first problem I removed the send of the "L2CAP information 
>>> request packet" in the kernel (see attached patch). This fixes both 
>>> problems.
>>>
>>> I did not found any usage of the remote L2CAP information in kernel.
>>> Is sending "L2CAP information request packet" mandatory for upper 
>>> layer and/or qualification ?
>>> Is my fix OK ?
>>
>> sending the L2CAP info is just fine. It should not cause any problems. I
>> think it is the pairing code that does some weird things at the wrong
>> time. Can you test with bluetooth-testing.git against bluez-4.28 to
>> verify that this issue still exists.
> 
> I try multiple configuration to test these 2 problems :
> 
> - pairing out failure with P800 or N70 :
>   - Ubuntu 8.04 + kernel 2.6.24.23 + BlueZ 3.26 => unable to pair (see 
> Ubuntu804_Bluez326_traces.txt)
>   - Ubuntu 8.04 + kernel 2.6.24.23 + BlueZ 4.28 => unable to pair (see 
> Ubuntu804_Bluez428_traces.txt)
>   - Ubuntu 8.10 + kernel 2.6.27.11 + BlueZ 4.12 => pairing OK (see 
> Ubuntu810_Bluez412_traces.txt)
> 
>   To perform pairing I use :
>   BlueZ 3.26 : dbus-send --system --type=method_call --print-reply 
> --dest=org.bluez /org/bluez/hci1 org.bluez.Adapter.CreateBonding 
> string:00:0A:D9:14:D0:85
>   BlueZ 4.xx : bluez-4.xx/test/simple-agent hci0 00:0A:D9:14:D0:85
> 
> - kernel crash with LG 990 :
>   - Ubuntu 8.04 + kernel 2.6.24.23 + BlueZ 3.26 => Ubuntu freeze (kernel 
> crash)
>   - Ubuntu 8.04 + kernel 2.6.24.23 + BlueZ 4.28 => Ubuntu freeze (kernel 
> crash)
>   - Ubuntu 8.10 + kernel 2.6.27.11 + BlueZ 4.12 => pairing OK
> 
> So, for me, it seems to be a problem in the kernel 2.6.24.
> What is your opinion ?
> 
> Unfortunately, I am not able to change kernel version. Do you have any 
> idea how to fix this, please ? Is my fix OK ?
> 
> Regards
> 
> Fred
> 
> 

Do you have any idea how to fix this, please ? Is my fix OK ?
Is there any problem (interoperability, qualification, ...) to remove L2CAP info request ?

Regards

Fred

-- 
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It is not by improving the oil lamp that one invents the electric bulb!
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Danis Frederic                   Access Company
Software engineer
Mail : mailto:frederic.danis@access-company.com
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