Re: [Bluez-users] Concurrent hcitool commands

["J. Carlos Alvarez" <jcalvar@movilok.com>]

Thanks a lot, Marcel.

Juan Carlos

Marcel Holtmann wrote:
> Hi Juan Carlos,
>
>   
>> we are trying to use hcitool to retrieve some information about 
>> several devices and we need to do it in parallel (several scripts 
>> concurrently call "hcitool name XX:XX:XX:XX:XX" using the same local 
>> device looking for the name of several remote devices).
>>
>> Doing this we found that some responses received from different remote 
>> devices were mixed, we obtained the same device name from two different 
>> remote devices.
>>
>> The following is a simple way to check this behaviour:
>> ---------------------------------------------------------------
>> [root@localhost~]# hcitool -i hci0 name 00:12:D1:DB:9A:E3
>> Nokia E70
>> [root@localhost~]# hcitool -i hci0 name 00:13:FD:FC:DE:50
>> Nokia 6680
>> [root@localhost~]# hcitool -i hci0 name 00:12:D1:DB:9A:E3 & hcitool -i 
>> hci0 name 00:13:FD:FC:DE:50
>> [1] 14223
>> Nokia E70
>> Nokia E70
>> [1]+  Done                    hcitool -i hci0 name 00:12:D1:DB:9A:E3
>> ---------------------------------------------------------------
>>
>> - The first command gets the right name of our E70 phone:
>>  "Nokia E70"
>>
>> - The second one also gets the right name of our 6680 phone:
>>  "Nokia 6680"
>>
>> - But if we invoke both commands concurrently, both "hcitool" calls get 
>> the same name as the device response:
>>  "Nokia E70"
>>  "Nokia E70"
>>
>> Are we doing something wrong?
>>
>> Is there any technical limitation related to this kind of requests so we 
>> must to do these calls serially?
>>     
>
> this is a known limitation. And in general you can't execute name
> request in parallel anyway. Every name request involves a baseband page
> and that takes time and these can't be done in parallel. However some
> chips create the illusion that they can.
>
> I would advise you to use the D-Bus interface since it does the name
> resolving in the background and automatically caches the resolved device
> names for you. No need to fiddle around with low-level commands.
>
> And in case of Bluetooth 2.1 devices with extended inquiry it will
> deliver the remote name for free with the inquiry response. That all
> works already and is completely hidden via D-Bus. So nothing for you to
> worry about.
>
> Regards
>
> Marcel
>
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> Bluez-users mailing list
> Bluez-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bluez-users
>
>   

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Bluez-users mailing list
Bluez-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-users