eSCO or SCO link?

Hi All,
 I have a stlc2500c which is a Bluetooth 1.2 chip. When debuging
function 'hci_connect', i found the hci link type of the arguments was
SCO_LINK, because i enabled 'lmp_esco_capable' in my kernel, it call
'hci_setup_sync' to setup eSCO link.
struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t
*dst, __u8 auth_type)
{
        .....
	if (lmp_esco_capable(hdev))
	{
		hci_setup_sync(sco, acl->handle);
	}			
	else
	{
		hci_add_sco(sco, acl->handle);
	}
		
}