When in sniff mode with a long interval time (1.28s) it can take 4+ seconds to
establish a SCO link. Fix by requesting active mode before requesting SCO
connection. This improves SCO setup time to ~500ms.
Bluetooth headsets that use a long interval time, and exhibit the long SCO
connection time include Motorola H790, HX1 and H17. They have a CSR 2.1 chipset
BD Address: 00:1A:0E:F2:68:65
Device Name: Motorola H790
LMP Version: 2.1 (0x4) LMP Subversion: 0x165d
Manufacturer: Cambridge Silicon Radio (10)
Features page 0: 0xdf 0xfe 0x0b 0xc0 0x1b 0xbe 0x59 0x83
<3-slot packets> <5-slot packets> <encryption> <slot offset>
<timing accuracy> <hold mode> <sniff mode> <RSSI>
<channel quality> <SCO link> <HV2 packets> <HV3 packets>
<u-law log> <A-law log> <CVSD> <paging scheme>
<transparent SCO> <inquiry with RSSI> <extended SCO>
<EV4 packets> <EV5 packets> <AFH cap. slave>
<AFH class. slave> <sniff subrating> <pause encryption>
<AFH cap. master> <AFH class. master> <EDR eSCO 2 Mbps>
<3-slot EDR eSCO> <extended inquiry> <simple pairing>
<encapsulated PDU> <non-flush flag> <LSTO> <inquiry TX power>
<extended features>
Features page 1: 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00
Verified this behavior and fix with host Bluetooth chipsets: BCM4329 and
TI1271.
Signed-off-by: Nick Pelly <[email protected]>
---
net/bluetooth/hci_conn.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index a975098..b3e0338 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -376,6 +376,7 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
if (acl->state == BT_CONNECTED &&
(sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
+ hci_conn_enter_active_mode(acl);
if (lmp_esco_capable(hdev))
hci_setup_sync(sco, acl->handle);
else
--
1.6.3.1