Hi Szymon, > On Monday, 27 March 2017 16:55:05 CEST Marcel Holtmann wrote: > > Hi Avinash, > > > > please also refrain from top posting. > > > > > Yes, for secure connection the LTK is generated locally. > > > But issue here is observed that after Pairing is complete the key > > > distribution is not completed from Master. > > > > > > i.e. After Slave sends the "Signature key:" but Master doesn't > > > share any key. Attached logs. > > I get that and that is clear from the logs. Something is stalling here > > and because of that, you run into the 30 seconds SMP timeout. We just > > need to know if the 4.9 kernel is doing this correctly. If so, then > > you can bi-sect that patch that fixes. Without proof that 4.9 is also > > broken, nobody will even bother to chase this down. > > I think the problem here is race between ACL data and HCI events on USB > dongle... We get initial slave keys but those get dropped due to encryption > changed event not being received yet. Since keys were silently dropped we later > on get unexpected SMP PDU and ignoring remaining keys as well which > eventually leads to SMP timeout. > > If this is USB dongle (using btusd) then only (AFAIK) solution would be to have a > workaround for this inside chip (it would delay ACL data received right after > encryption change giving host time to handle encpryption change event). > Bluetooth specification for USB transport is unfortunatelly kinda broken. > > -- > pozdrawiam > Szymon Janc Thank you for your reply. Your inputs are valuable to us in helping to debug the issue. Yes, we are indeed using the btusb kernel module and it is using a USB interface (Bluetooth over USB). I noticed that when btmgmt settings are set to turn 'bredr off', the 'ssp' mode also turns off. Is this behavior expected to occur? My current settings are 'powered connectable discoverable bondable le secure-conn' Thank you. Best regards, Joshua -- 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
