Hello Marcel and Luiz, Thanks for looking at the patch! > On Jul 15, 2017, at 2:03 PM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote: > >>> --- a/doc/device-api.txt >>> +++ b/doc/device-api.txt >>> @@ -234,3 +234,8 @@ Properties string Address [readonly] >>> array{byte} AdvertisingFlags [readonly, experimental] >>> >>> The Advertising Data Flags of the remote device. >>> + >>> + int16 NegotiatedMTU [readonly, optional, experimental] >>> + >>> + The ATT MTU negotiated with the connected host. >>> + Available only once MTU negotiation is complete. >> >> Despite being odd that we start exposing transport specific details on >> device interface, there maybe a chance this is useful if we can >> properly detect BR/EDR MTU not only LE, though this means checking the >> via bt_att API not bt_gatt_server. Obviously, this would have to be >> exposed even before it is negotiated since LE start with 23 but on >> BR/EDR this is negotiated via L2CAP signaling, and perhaps it should >> not really be MTU that we expose but the actual payload without the >> headers that bluetoothd takes care of adding. > > I think that exposing max payload is a better idea. I am fine with the revised naming, and revising the exposed device attribute to represent the max ATT payload. However, how can a dbus client know whether the MTU negotiation has occurred or not? The point of the patch is to allow for clients to take advantage of a larger negotiated MTU. The negotiation of the MTU can be a significant event to the client interacting via dbus, so how should the completion of that negotiation be exposed, if not via an attribute as I proposed above? Some boolean "MaxPayloadNegotiationCompleted" method? Jonah-- 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