From 52f5e0d41a2c757eb1f9e5c39268f6f2797cad46 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Mon, 14 Aug 2017 16:46:38 +0200
Subject: [PATCH] Make the initialization sequence more flexible

According to the SD specification v2.00 we this is the right way to
initialize a card using the v1 protocol in a forward-compatible way.
---
 SDBlockDevice.cpp | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/SDBlockDevice.cpp b/SDBlockDevice.cpp
index 3dc70cc128..d31b2e1f5e 100644
--- a/SDBlockDevice.cpp
+++ b/SDBlockDevice.cpp
@@ -274,14 +274,13 @@ int SDBlockDevice::_initialise_card()
         return SD_BLOCK_DEVICE_ERROR_NO_DEVICE;
     }
 
-    // Send CMD8
-    if (BD_ERROR_OK != (status = _cmd8())) {
+    // Send CMD8, if the card rejects the command then it's probably using the
+    // legacy protocol, or is a MMC, or just flat-out broken
+    status = _cmd8();
+    if (BD_ERROR_OK != status && SD_BLOCK_DEVICE_ERROR_UNSUPPORTED != status) {
         return status;
     }
 
-    // Disable CRC
-    status = _cmd(CMD59_CRC_ON_OFF, 0);
-
     // Read OCR - CMD58 Response contains OCR register
     if (BD_ERROR_OK != (status = _cmd(CMD58_READ_OCR, 0x0, 0x0, &response))) {
         return status;
@@ -333,6 +332,10 @@ int SDBlockDevice::_initialise_card()
         _card_type = SDCARD_V1;
         debug_if(SD_DBG, "Card Initialized: Version 1.x Card\n");
     }
+
+    // Disable CRC
+    status = _cmd(CMD59_CRC_ON_OFF, 0);
+
     return status;
 }