Hi Sergey,
>>>>>> The MediaTek Bluetooth platform (MT6630 etc.) has a peculiar
>>>>>> implementation
>>>>>> for the eSCO/SCO connection via BT/EDR: the host controller returns error
>>>>>> code 0x20 (LMP feature not supported) for
>>>>>> HCI_Setup_Synchronous_Connection
>>>>>> (0x0028) command without actually trying to setup connection with a
>>>>>> remote
>>>>>> device in case such device (like Digma BT-14 headset) didn't advertise
>>>>>> its
>>>>>> supported features. Even though this doesn't break compatibility with
>>>>>> the
>>>>>> Bluetooth standard it breaks the compatibility with the Hands-Free
>>>>>> Profile
>>>>>> (HFP).
>>>>>>
>>>>>> This patch returns the compatibility with the HFP profile and actually
>>>>>> tries to check all available connection parameters despite of the
>>>>>> specific
>>>>>> MediaTek implementation. Without it one was unable to establish eSCO/SCO
>>>>>> connection with some headsets.
> [...]
>>>>>> Signed-off-by: Sergey Shtylyov <s.shtyl...@omprussia.ru>
>>>>>>
>>>>>> ---
>>>>>> This patch is against the 'bluetooth-next.git' repo.
>>>>>>
>>>>>> net/bluetooth/hci_event.c | 8 ++++++++
>>>>>> 1 file changed, 8 insertions(+)
>>>>>>
>>>>>> Index: bluetooth-next/net/bluetooth/hci_event.c
>>>>>> ===================================================================
>>>>>> --- bluetooth-next.orig/net/bluetooth/hci_event.c
>>>>>> +++ bluetooth-next/net/bluetooth/hci_event.c
>>>>>> @@ -2187,6 +2187,13 @@ static void hci_cs_setup_sync_conn(struc
>>>>>> if (acl) {
>>>>>> sco = acl->link;
>>>>>> if (sco) {
>>>>>> + if (status == 0x20 && /* Unsupported LMP
>>>>>> Parameter value */
>>>>>> + sco->out) {
>>
>> Actually, I was expecting that you'd tell me to create a HCI quirk for
>> this situation.
>> I have a patch doing that but I haven't been able to locate the driver in
>> which to set this
>> quirk flag...
>
> And that's no wonder! The BT driver that needs this patch is out-of-tree
> (and not even open
> source, it seems) as we have finally ascertained with Ildar... Is there any
> interest in the
> "preparatory" patch that lowers the indentation levels in
> hci_cs_setup_sync_conn()?
how is it possible that there is an out-of-tree Bluetooth driver. Seems odd.
Maybe want to submit that upstream first.
Regards
Marcel
