From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <003101c4ca02$b9f20d90$6f04a8c0@ZBOX> From: "Suriyan" To: References: <20041110041405.3CC331D4758@sc8-sf-uberspam1.sourceforge.net> MIME-Version: 1.0 Content-Type: text/plain; charset=windows-874 Subject: [Bluez-devel] Re: multi rfcomm/sco connection Sender: bluez-devel-admin@lists.sourceforge.net Errors-To: bluez-devel-admin@lists.sourceforge.net Reply-To: bluez-devel@lists.sourceforge.net List-Unsubscribe: , List-Id: BlueZ development List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sun, 14 Nov 2004 11:30:52 +0700 Hi Marcel, I just found the way to work with three headsets over only one Bluetooth dongle by a few hardcoded to BlueZ:- 1. force alternate setting of USB interface number 1, isochronous endpoint to 5 (3 voice channels with 16 bit encoding) when three SCO channels connected (by run three hsplay consecutively) I found each incoming SCO HCI frame size up to 144 bytes (as I known previously one voice channel with 16-bit encoding SCO HCI frame size equals 48 bytes so that three channels 48 * 3 = 144 bytes) This mean one HCI frame to transmit/receive for each SCO channel over USB isochronous endpoint when three SCO channels were connected have frame size equals 144 bytes + 3 bytes header (handle and size) but I not sure this is CSR specific since Bluetooth HCI USB transport specification (H:2) have not details in this point, define only suggested Max Packet Size of each USB frame for transport SCO HCI frame. This cause I must do the second step, 2. bypass checking (skb->len > hdev->sco_mtu) in function hci_send_sco(...) [hci_core.c] and (len > conn->mtu) in function sco_send_frame(...) [sco.c] *** I just think, this step maybe change by hciconfig tool. *** Next step, I would like to fixed to dynamicaly change the alternate setting by looking for previous thread "question about hci_usb endpoint selection..." as you known in notify() cannot call usb_set_interface() since always in_interrupt() so that I would like to purpose to add ioctl() into hci_usb driver to do this or do you have others better approach? Last, I found new problem when three SCO channels were connected ACL links (RFCOMM) that also connected to three Headset for control have very long response time (sometime up to 10 seconds or more to appear after I pressed a button on Headset). What are the sources of this problem? - Bandwidth limitation of Bluetooth and theirs packet type? - Implementation of Bluetooth firmware on USB dongle? - Implementation of USB stack on Linux? - Implementation of BlueZ stack? Regards Suriyan. ------------------------------------------------------- This SF.Net email is sponsored by: InterSystems CACHE FREE OODBMS DOWNLOAD - A multidimensional database that combines robust object and relational technologies, making it a perfect match for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8 _______________________________________________ Bluez-devel mailing list Bluez-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-devel/listinfo/bluez-devel