Hi Fabien, On Tue, Sep 25, 2018, fabien dvlt wrote: > > ACL Data RX: Handle 13 flags 0x02 dlen 12 #198 [hci0] 21.813116 > L2CAP: Connection Request (0x02) ident 7 len 4 > PSM: 25 (0x0019) > Source CID: 75 > > HCI Event: Encryption Change (0x08) plen 4 #199 [hci0] 21.813155 > Status: Success (0x00) > Handle: 13 > Encryption: Enabled with AES-CCM (0x02) > < ACL Data TX: Handle 13 flags 0x00 dlen 16 #200 [hci0] > L2CAP: Connection Response (0x03) ident 7 len 8 > Destination CID: 0 > Source CID: 75 > Result: Connection refused - security block (0x0003) > Status: No further information available (0x0000) This looks like the well-known race condition for ACL data and HCI events on USB where the two come through different endpoints. From the host perspective there's not much we can do since we can't make assumptions that the connection request was sent over an encrypted connection if we haven't seen the encryption change request at that point. Johan
