Thread (9 messages) flat view 9 messages, 2 authors, 2014-09-23

Re: [PATCHv3 1/1] bluetooth: Check for SCO type before setting retransmission effort

From: Marcel Holtmann <marcel@holtmann.org>
Date: 2014-09-23 07:44:41
Also in: linux-bluetooth, lkml

Hi Bernhard,
quoted hunk ↗ jump to hunk
SCO connection cannot be setup to devices that do not support retransmission.
Patch based on http://permalink.gmane.org/gmane.linux.bluez.kernel/7779 and
adapted for this kernel version.
Code changed to check SCO/eSCO type before setting retransmission effort
and max. latency. The purpose of the patch is to support older devices not
capable of eSCO.

Tested on Blackberry 655+ headset which does not support retransmission.
Credits go to Alexander Sommerhuber.

Signed-off-by: Bernhard Thaler <redacted>
---
net/bluetooth/hci_conn.c |   22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index faff624..32dcde1 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -38,7 +38,7 @@ struct sco_param {
	u16 max_latency;
};

-static const struct sco_param sco_param_cvsd[] = {
+static const struct sco_param esco_param_cvsd[] = {
	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x000a }, /* S3 */
	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x0007 }, /* S2 */
	{ EDR_ESCO_MASK | ESCO_EV3,   0x0007 }, /* S1 */
@@ -46,6 +46,11 @@ static const struct sco_param sco_param_cvsd[] = {
	{ EDR_ESCO_MASK | ESCO_HV1,   0xffff }, /* D0 */
};

+static const struct sco_param sco_param_cvsd[] = {
+	{ EDR_ESCO_MASK | ESCO_HV3,   0xffff }, /* D1 */
+	{ EDR_ESCO_MASK | ESCO_HV1,   0xffff }, /* D0 */
+};
+
static const struct sco_param sco_param_wideband[] = {
	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x000d }, /* T2 */
	{ EDR_ESCO_MASK | ESCO_EV3,   0x0008 }, /* T1 */
@@ -194,10 +199,17 @@ bool hci_setup_sync(struct hci_conn *conn, __u16 handle)
		param = &sco_param_wideband[conn->attempt - 1];
		break;
	case SCO_AIRMODE_CVSD:
-		if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
-			return false;
-		cp.retrans_effort = 0x01;
-		param = &sco_param_cvsd[conn->attempt - 1];
+		if (!lmp_esco_capable(conn->link)) {
please change this statement around to check if eSCO support exists and not if it does not exist. The negation is pointless if you have an else branch anyway.
+			if ((conn->attempt) > ARRAY_SIZE(sco_param_cvsd))
The extra (conn->attempt) is not needed. Just do (conn->attempt > ARRAY_SIZE(..))
+				return false;
+			cp.retrans_effort = 0xff;
+			param = &sco_param_cvsd[conn->attempt - 1];
+		} else {
+			if (conn->attempt > ARRAY_SIZE(esco_param_cvsd))
+				return false;
+			cp.retrans_effort = 0x01;
+			param = &esco_param_cvsd[conn->attempt - 1];
+		}
		break;
	default:
		return false;
The rest looks fine.

Regards

Marcel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help