Hi,I was surprised to not see a possibility to configure the latency used for (e)SCO connection during creation or accept phase.
the kernel code shows simply this (in any git repo I check) net/bluetooth/hci_conn.c: hci_setup_sync()164 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l164> void hci_setup_sync(struct hci_conn *conn, __u16 handle) 165 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l165> { 166 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l166> struct hci_dev *hdev = conn->hdev; 167 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l167> struct hci_cp_setup_sync_conn cp; 168 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l168> 169 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l169> BT_DBG("%p", conn); 170 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l170> 171 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l171> conn->state = BT_CONNECT; 172 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l172> conn->out = 1; 173 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l173> 174 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l174> conn->attempt++; 175 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l175> 176 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l176> cp.handle = cpu_to_le16(handle); 177 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l177> cp.pkt_type = cpu_to_le16(conn->pkt_type); 178 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l178> 179 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l179> cp.tx_bandwidth = cpu_to_le32(0x00001f40); 180 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l180> cp.rx_bandwidth = cpu_to_le32(0x00001f40); 181 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l181> cp.max_latency = cpu_to_le16(0xffff); <<<<<< static configuration 182 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l182> cp.voice_setting = cpu_to_le16(hdev->voice_setting); 183 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l183> cp.retrans_effort = 0xff; 184 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l184> 185 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l185> hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp); 186 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l186> } 187 <http://git.kernel.org/?p=linux/kernel/git/padovan/bluetooth-2.6.git;a=blob;f=net/bluetooth/hci_conn.c;h=ea7f031f3b04607efc65e79ab061dd0c5cb9337c;hb=refs/heads/master#l187>
What could be a way to add the feature without breaking any API 1) use the MTU of the socket or hdev ?2) add hdev entry for sco latency (which can be configured with hciconfig like voice settings)
3) something else ... or 4) no one cares about latency... PS: the same way, the retransmit effort is not configurable today. regards, arnaud -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
