LLCP with Android 2.3 (Nexus S)

Written for nfcpy by Stephen Tiedemann on 2011-05-03

Android 2.3 has LLCP and allows sending NDEF across another phone, but did not immediately work with nfcpy. Actually running nothing else than the llcp-test-server should make the phone least exchange symmetry packets with nfcpy quite happily. Turned out that the LLCP stack on the Nexus S is still a little buggy, it doesn't support aggregation of PDUs (i.e. can't disaggregate) and if it becomes the NFC-DEP Target looses the first PDU if that comes within the first 100 ms after LLCP link activation. Until that gets fixed, an nfcpy user code needs to delay 100 ms if it has become Initiator and must set the new configuration option "send-agf" as false. For the llcp-test-client and server the command line flag "--quirks=android" will do the trick.