From b7a74931f6225c44b01ca548e8c90b3bb3f91843 Mon Sep 17 00:00:00 2001
From: Romuald Conty <romuald@libnfc.org>
Date: Sun, 3 Jun 2012 21:02:31 +0000
Subject: [PATCH] Returns a NFC_ETGRELEASED error when MIFARE Classic's
 authentication failed (instead of NFC_ECHIP): a MIFARE Classic is halted on
 AUTH command failure.

---
 libnfc/chips/pn53x.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libnfc/chips/pn53x.c b/libnfc/chips/pn53x.c
index 52f3592..7fb0b67 100644
--- a/libnfc/chips/pn53x.c
+++ b/libnfc/chips/pn53x.c
@@ -267,6 +267,10 @@ pn53x_transceive(struct nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx
     case ECDISCARDED:
       res = NFC_ETGRELEASED;
       break;
+    case EMFAUTH:
+      // When a MIFARE Classic AUTH fails, the tag is automatically in HALT state
+      res = NFC_ETGRELEASED;
+      break;
     default:
       res = NFC_ECHIP;
       break;