From f37c64ee5b640ef9c2e295db792c34c9f1f8369f Mon Sep 17 00:00:00 2001
From: GMagician <GMagician@users.noreply.github.com>
Date: Sat, 13 Jan 2018 08:53:12 +0100
Subject: [PATCH] Fix unsupported CMD59

It seems that some SD cards don't support CRC_ON_OFF command. This fix will permit to use also these cards but leaving CRC check active on the system
---
 Marlin/src/sd/Sd2Card.cpp | 9 ++++-----
 Marlin/src/sd/Sd2Card.h   | 2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/Marlin/src/sd/Sd2Card.cpp b/Marlin/src/sd/Sd2Card.cpp
index 4392c06b2..adecc8e61 100644
--- a/Marlin/src/sd/Sd2Card.cpp
+++ b/Marlin/src/sd/Sd2Card.cpp
@@ -41,6 +41,8 @@
 #include "../Marlin.h"
 
 #if ENABLED(SD_CHECK_AND_RETRY)
+  static bool crcSupported = true;
+
   #ifdef FAST_CRC
     static const uint8_t crctab7[] PROGMEM = {
       0x00,0x09,0x12,0x1b,0x24,0x2d,0x36,0x3f,0x48,0x41,0x5a,0x53,0x6c,0x65,0x7e,0x77,
@@ -267,10 +269,7 @@ bool Sd2Card::init(uint8_t sckRateID, pin_t chipSelectPin) {
   }
 
 #if ENABLED(SD_CHECK_AND_RETRY)
-  if (cardCommand( CMD59, 1 ) != R1_IDLE_STATE) {
-    error(SD_CARD_ERROR_CMD59);
-    goto FAIL;
-  }
+  crcSupported = (cardCommand(CMD59, 1) == R1_IDLE_STATE);
 #endif
 
   // check SD version
@@ -450,7 +449,7 @@ bool Sd2Card::readData(uint8_t* dst, uint16_t count) {
 #if ENABLED(SD_CHECK_AND_RETRY)
   {
     uint16_t recvCrc = (spiRec() << 8) | spiRec();
-    if (recvCrc != CRC_CCITT(dst, count)) {
+    if (crcSupported && recvCrc != CRC_CCITT(dst, count)) {
       error(SD_CARD_ERROR_READ_CRC);
       goto FAIL;
     }
diff --git a/Marlin/src/sd/Sd2Card.h b/Marlin/src/sd/Sd2Card.h
index 65633aa8c..0df9c0ba6 100644
--- a/Marlin/src/sd/Sd2Card.h
+++ b/Marlin/src/sd/Sd2Card.h
@@ -71,7 +71,7 @@ uint8_t const SD_CARD_ERROR_CMD0 = 0x01,                // timeout error for com
               SD_CARD_ERROR_WRITE_TIMEOUT = 0x17,       // timeout occurred during write programming
               SD_CARD_ERROR_SCK_RATE = 0x18,            // incorrect rate selected
               SD_CARD_ERROR_INIT_NOT_CALLED = 0x19,     // init() not called
-              SD_CARD_ERROR_CMD59 = 0x1A,               // card returned an error for CMD59 (CRC_ON_OFF)
+              // 0x1A is unused now, it was: card returned an error for CMD59 (CRC_ON_OFF)
               SD_CARD_ERROR_READ_CRC = 0x1B;            // invalid read CRC
 
 // card types