NFC: Handle SHDLC RSET frames from an SHDLC connected chip

shdlc reset may leave HCI in an inconsistent state by loosing parts of
HCI frames. Handle this case by reporting an unrecoverable error to HCI.

Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

net/nfc/hci/shdlc.c

@@ -404,12 +404,12 @@ static void nfc_shdlc_rcv_u_frame(struct nfc_shdlc *shdlc,
 				r = nfc_shdlc_connect_send_ua(shdlc);
 				nfc_shdlc_connect_complete(shdlc, r);
 			}
-		} else if (shdlc->state > SHDLC_NEGOCIATING) {
+		} else if (shdlc->state == SHDLC_CONNECTED) {
 			/*
-			 * TODO: Chip wants to reset link
-			 * send ua, empty skb lists, reset counters
-			 * propagate info to HCI layer
+			 * Chip wants to reset link. This is unexpected and
+			 * unsupported.
 			 */
+			shdlc->hard_fault = -ECONNRESET;
 		}
 		break;
 	case U_FRAME_UA: