From ce418fb72067f01c2044127af5fb903f52606cc8 Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Thu, 15 Mar 2018 19:59:33 +0100
Subject: [PATCH] chg: 'hf mfu read' chg: 'hf mfu dump'  - 5 retries if failed
 readblock.  Loop for CRC error or incomplete reads.

This will make reading / dumping more stable.
---
 armsrc/mifareutil.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/armsrc/mifareutil.c b/armsrc/mifareutil.c
index afb9fdd8c..8e158a91b 100644
--- a/armsrc/mifareutil.c
+++ b/armsrc/mifareutil.c
@@ -334,7 +334,7 @@ int mifare_ultra_auth(uint8_t *keybytes){
 	return 1;
 }
 
-int mifare_ultra_readblock(uint8_t blockNo, uint8_t *blockData) {
+int mifare_ultra_readblockEx(uint8_t blockNo, uint8_t *blockData) {
 	uint16_t len = 0;
 	uint8_t	bt[2] = {0x00, 0x00};
 	uint8_t receivedAnswer[MAX_FRAME_SIZE] = {0x00};
@@ -360,6 +360,25 @@ int mifare_ultra_readblock(uint8_t blockNo, uint8_t *blockData) {
 	memcpy(blockData, receivedAnswer, 14);
 	return 0;
 }
+int mifare_ultra_readblock(uint8_t blockNo, uint8_t *blockData) {
+	#define MFU_MAX_CRC_RETRIES 5
+	uint8_t retries = 0;
+	uint8_t res;
+	
+	for (retries = 0; retries < MFU_MAX_CRC_RETRIES; ++retries) {
+		res = mifare_ultra_readblockEx(blockNo, blockData);
+		
+		// break if OK,  or NACK.
+		switch ( res ) {
+			case 0:
+			case 1:
+				break;
+			default:
+				continue;
+		}
+	}
+	return res;
+}
 
 int mifare_classic_writeblock(struct Crypto1State *pcs, uint32_t uid, uint8_t blockNo, uint8_t *blockData) {
 	// variables