From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> This set of patches uses the priority of the socket, set via SO_PRIORITY, to prioritized data over HCI. Current priority range is from 0-7, where 0-6 priority can be set without any exatra capability which is according to SO_PRIORITY documentation (socket(7)): SO_PRIORITY Set the protocol-defined priority for all packets to be sent on this socket. Linux uses this value to order the networking queues: packets with a higher priority may be processed first depending on the selected device queueing discipline.... Setting a priority outside the range 0 to 6 requires the CAP_NET_ADMIN capability. This also enables in the future the use of guaranteed channels as it is necessary to prioritized them over best effort (default) channels, Bluetooth V4.0 spec (page 1497): 7.9 PRIORITIZING DATA OVER HCI In order for guaranteed channels to meet their guarantees, L2CAP should prioritize traffic over the HCI transport in devices that support HCI. Packets for Guaranteed channels should receive higher priority than packets for Best Effort channels. Note: to be able to use guaranteed channels we need to negotiate QoS parameters both in L2CAP and HCI, this is outside of the scope of this patches since it probably requires new socket options to L2CAP sockets. The main use case for this is A2DP, many people complained that when they are using their HID devices (mouses) together with headset the mouse has higher priority, which btw is not true since currently there is no priority and connections receives the same quote. With this changes it may reduce the problem since PulseAudio already sets A2DP socket as low latency (priority 6), which means audio packets will be processed before the HID packets, but this only affects tx and there still exist the problem of some HID not letting us being master. Ive been testing this using A2DP and HID connected simultaneusly without a problem, though connecting/paging still makes audio skips, and also tried OBEX transfers together to see if audio skips, indeed it does when HID is active but it works better than having no priority (skips less frequent) and in case of using priority 7 the audio doesn't skip anymore but it eventually stall the OBEX transfer (this is maybe because OpenOBEX loop while trying to write to socket and don't wait for POLLOUT). Luiz Augusto von Dentz (3): Bluetooth: prioritizing data over HCI Bluetooth: set skbuffer priority based on L2CAP socket priority Bluetooth: make use sk_priority to priritize RFCOMM packets include/net/bluetooth/hci_core.h | 6 ++- include/net/bluetooth/l2cap.h | 3 +- net/bluetooth/hci_conn.c | 8 ++- net/bluetooth/hci_core.c | 141 +++++++++++++++++++++++++++---------- net/bluetooth/l2cap_core.c | 47 +++++++++---- net/bluetooth/l2cap_sock.c | 2 +- net/bluetooth/rfcomm/core.c | 51 +++++++++---- net/bluetooth/rfcomm/sock.c | 8 ++ 8 files changed, 194 insertions(+), 72 deletions(-) -- 1.7.6 -- 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
