Hi Marcel, When we connect a SCO socket, BlueZ decides whether to connect SCO or eSCO type according to the remote feature. If the remote device declares supporting eSCO in the remote feature, BlueZ will select eSCO type to connect with it. But in fact there are some old carkits or headsets which are only support SCO but wrongly declare to support eSCO, such as Motorola HF850 and HS820 which use a very old CSR chip, so we have problem to create sco connection with them. We thought a method to resolve this issue, which is force to create SCO type connection if we find the HFP version of one remote device is less than 1.2. So we need a method to control the SCO type from user space. We want to use setsockopt() functon to do that. The code change in net/bluetooth/sco.c is like below, @@ -653,12 +653,25 @@ static int sco_sock_setsockopt(struct socket *sock, int le { struct sock *sk = sock->sk; int err = 0; + u32 opt; BT_DBG("sk %p", sk); lock_sock(sk); + if (level != SOL_SCO) { + err = -ENOPROTOOPT; + return err; + } + switch (optname) { + case BT_DISABLE_ESCO: + if (get_user(opt, (u32 __user *) optval)) { + err = -EFAULT; + break; + } + disable_esco = opt; + break; default: err = -ENOPROTOOPT; break; Then, in the user space, we can call setsockopt(fd, SOL_SCO, BT_DISABLE_ESCO, &disabled, sizeof(disabled)) to force to connect SCO. Do you agree with this change? Thanks, Zhu Lan -- 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