[Bluez-devel] Question about BlueZ and RFCOMM

[Bluez-devel] Question about BlueZ and RFCOMM

[Dave Sweetser]

Hi,

I have a question about using RFCOMM on BlueZ.  Here is our system:

   
    Linux system with    <-----over the air------->  CSR BC03-MM chip and
    CSR-based USB dongle                             the STMicroelectronics 
                                                     STR710 ARM
Microprocessor
                                                     ("micro")


We want to use the BlueZ RFCOMM library.  On the microprocessor side, I'm
using the serial
port of the CSR Bluetooth chip so I am able to monitor the serial data
stream between the
CSR Bluetooth chip and the microprocessor ("micro").

Most of the RFCOMM communication works fine.  On the micro side, I observe
that the
parameter negotiation happens OK and the RFCOMM connection is established.
However,
the data I try to send from the Linux system is never received by the micro.
What
happens instead is that the micro receives these commands from the Bluetooth
chip
(these are in CSR's format):
                                RFC_CONTROL_IND
                                RFC_RELEASE_IND
                                RFC_CLOSE_IND
                                DM_ACL_CLOSED_IND

I also observe that the Linux system, while connection is being established,
is sending
flow control messages (3, in my case) to the micro.  These are with a credit
field of 
4, 5 and 6 for the 3 flow control messages.

Now to my question: Does the micro need to respond to these flow control
messages in some
                    manner to maintain the RFCOMM connection?  Currently the
micro doesn't 
                    respond to the flow control messages.

If it is OK for the micro to not respond to the flow control messages, can
someone help me
understand what else might be causing the RFCOMM data to not be sent from
the Linxu system
and what might be causing the RFCOMM connection to be closed down?

Thank you very much for your help!  Please let me know if I can provide
additional information.

Dave Sweetser

P.S. I'm assuming my problem is independent of the version of Linux and also
independent of the
     version of BlueZ (which is the latest) -- if you need this information,
however, just let me know.



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Re: [Bluez-devel] Question about BlueZ and RFCOMM

[Marcel Holtmann]

Hi Dave,

> I have a question about using RFCOMM on BlueZ.  Here is our system:
> 
>    
>     Linux system with    <-----over the air------->  CSR BC03-MM chip and
>     CSR-based USB dongle                             the STMicroelectronics 
>                                                      STR710 ARM
> Microprocessor
>                                                      ("micro")
> 
> 
> We want to use the BlueZ RFCOMM library.  On the microprocessor side, I'm
> using the serial
> port of the CSR Bluetooth chip so I am able to monitor the serial data
> stream between the
> CSR Bluetooth chip and the microprocessor ("micro").
> 
> Most of the RFCOMM communication works fine.  On the micro side, I observe
> that the
> parameter negotiation happens OK and the RFCOMM connection is established.
> However,
> the data I try to send from the Linux system is never received by the micro.
> What
> happens instead is that the micro receives these commands from the Bluetooth
> chip
> (these are in CSR's format):
>                                 RFC_CONTROL_IND
>                                 RFC_RELEASE_IND
>                                 RFC_CLOSE_IND
>                                 DM_ACL_CLOSED_IND
> 
> I also observe that the Linux system, while connection is being established,
> is sending
> flow control messages (3, in my case) to the micro.  These are with a credit
> field of 
> 4, 5 and 6 for the 3 flow control messages.
> 
> Now to my question: Does the micro need to respond to these flow control
> messages in some
>                     manner to maintain the RFCOMM connection?  Currently the
> micro doesn't 
>                     respond to the flow control messages.
> 
> If it is OK for the micro to not respond to the flow control messages, can
> someone help me
> understand what else might be causing the RFCOMM data to not be sent from
> the Linxu system
> and what might be causing the RFCOMM connection to be closed down?

these question should be towards CSR, because you have problems with
their embedded RFCOMM stack. I have not enough insights to answer this
properly.

Regards

Marcel



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