From f4a3999f6f0d088b0ea2c41976e330a3322c5fee Mon Sep 17 00:00:00 2001
From: Tim <tdhutt@gmail.com>
Date: Mon, 31 Mar 2014 11:19:28 +0100
Subject: [PATCH] Fix for 32 bit processors.

The time-outs do not ever time-out on 32 bit processors if t0 happens to be close to 65535. This means that if you try to open an SD card that isn't present your app will sometimes freeze entirely in card.init() rather than returning an error like it is supposed to.
---
 libraries/SD/utility/Sd2Card.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/libraries/SD/utility/Sd2Card.cpp b/libraries/SD/utility/Sd2Card.cpp
index 361cd0a06db..5cdc8f7c4d2 100644
--- a/libraries/SD/utility/Sd2Card.cpp
+++ b/libraries/SD/utility/Sd2Card.cpp
@@ -241,7 +241,7 @@ uint8_t Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
 
   // command to go idle in SPI mode
   while ((status_ = cardCommand(CMD0, 0)) != R1_IDLE_STATE) {
-    if (((uint16_t)millis() - t0) > SD_INIT_TIMEOUT) {
+    if ((uint16_t)((uint16_t)millis() - t0) > SD_INIT_TIMEOUT) {
       error(SD_CARD_ERROR_CMD0);
       goto fail;
     }
@@ -263,7 +263,7 @@ uint8_t Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
 
   while ((status_ = cardAcmd(ACMD41, arg)) != R1_READY_STATE) {
     // check for timeout
-    if (((uint16_t)millis() - t0) > SD_INIT_TIMEOUT) {
+    if ((uint16_t)((uint16_t)millis() - t0) > SD_INIT_TIMEOUT) {
       error(SD_CARD_ERROR_ACMD41);
       goto fail;
     }
@@ -474,7 +474,7 @@ uint8_t Sd2Card::waitNotBusy(uint16_t timeoutMillis) {
   do {
     if (spiRec() == 0XFF) return true;
   }
-  while (((uint16_t)millis() - t0) < timeoutMillis);
+  while ((uint16_t)((uint16_t)millis() - t0) < timeoutMillis);
   return false;
 }
 //------------------------------------------------------------------------------
@@ -482,7 +482,7 @@ uint8_t Sd2Card::waitNotBusy(uint16_t timeoutMillis) {
 uint8_t Sd2Card::waitStartBlock(void) {
   uint16_t t0 = millis();
   while ((status_ = spiRec()) == 0XFF) {
-    if (((uint16_t)millis() - t0) > SD_READ_TIMEOUT) {
+    if ((uint16_t)((uint16_t)millis() - t0) > SD_READ_TIMEOUT) {
       error(SD_CARD_ERROR_READ_TIMEOUT);
       goto fail;
     }