diff --git a/examples/OpenNext/OpenNext.ino b/examples/OpenNext/OpenNext.ino
index 56329b4c..d88a49d9 100644
--- a/examples/OpenNext/OpenNext.ino
+++ b/examples/OpenNext/OpenNext.ino
@@ -10,6 +10,7 @@ const uint8_t chipSelect = SS;
 // file system object
 SdFat sd;
 
+SdFile root;
 SdFile file;
 //------------------------------------------------------------------------------
 void setup() {
@@ -30,12 +31,13 @@ void setup() {
   if (!sd.begin(chipSelect, SD_SCK_MHZ(50))) {
     sd.initErrorHalt();
   }
-
-  // Open next file in root.  The volume working directory, vwd, is root.
-  // Warning, openNext starts at the current position of sd.vwd() so a
-  // rewind may be neccessary in your application.
-  sd.vwd()->rewind();
-  while (file.openNext(sd.vwd(), O_RDONLY)) {
+  if (!root.open("/")) {
+    sd.errorHalt("open root failed");
+  }
+  // Open next file in root.
+  // Warning, openNext starts at the current directory position
+  // so a rewind of the directory may be required.
+  while (file.openNext(&root, O_RDONLY)) {
     file.printFileSize(&Serial);
     Serial.write(' ');
     file.printModifyDateTime(&Serial);
@@ -48,7 +50,11 @@ void setup() {
     Serial.println();
     file.close();
   }
-  Serial.println("Done!");
+  if (root.getError()) {
+    Serial.println("openNext failed");
+  } else {
+    Serial.println("Done!");
+  }
 }
 //------------------------------------------------------------------------------
 void loop() {}
diff --git a/library.properties b/library.properties
index 07088fa6..d00bcedb 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=SdFat
-version=1.0.14
+version=1.0.15
 author=Bill Greiman <fat16lib@sbcglobal.net>
 maintainer=Bill Greiman <fat16lib@sbcglobal.net>
 sentence=FAT16/FAT32 file system for SD cards.
diff --git a/src/FatLib/FatFile.h b/src/FatLib/FatFile.h
index 616959e0..0c043d5b 100644
--- a/src/FatLib/FatFile.h
+++ b/src/FatLib/FatFile.h
@@ -141,9 +141,11 @@ class FatFile {
    * LS_SIZE - %Print file size.
    *
    * LS_R - Recursive list of subdirectories.
+   *
+   * \return true for success or false if an error occurred.
    */
-  void ls(uint8_t flags = 0) {
-    ls(&Serial, flags);
+  bool ls(uint8_t flags = 0) {
+    return ls(&Serial, flags);
   }
   /** %Print a directory date field.
    *
@@ -464,8 +466,10 @@ class FatFile {
    *
    * \param[in] indent Amount of space before file name. Used for recursive
    * list to indicate subdirectory level.
+   *
+   * \return true for success or false if an error occurred.
    */
-  void ls(print_t* pr, uint8_t flags = 0, uint8_t indent = 0);
+  bool ls(print_t* pr, uint8_t flags = 0, uint8_t indent = 0);
   /** Make a new directory.
    *
    * \param[in] dir An open FatFile instance for the directory that will
diff --git a/src/FatLib/FatFilePrint.cpp b/src/FatLib/FatFilePrint.cpp
index e5785557..5cc79e8a 100644
--- a/src/FatLib/FatFilePrint.cpp
+++ b/src/FatLib/FatFilePrint.cpp
@@ -96,12 +96,16 @@ void FatFile::dmpFile(print_t* pr, uint32_t pos, size_t n) {
   pr->write('\n');
 }
 //------------------------------------------------------------------------------
-void FatFile::ls(print_t* pr, uint8_t flags, uint8_t indent) {
+bool FatFile::ls(print_t* pr, uint8_t flags, uint8_t indent) {
   FatFile file;
+  if (!isDir() || getError()) {
+    DBG_FAIL_MACRO;
+    goto fail;
+  }
   rewind();
   while (file.openNext(this, O_RDONLY)) {
-    // indent for dir level
     if (!file.isHidden() || (flags & LS_A)) {
+    // indent for dir level
       for (uint8_t i = 0; i < indent; i++) {
         pr->write(' ');
       }
@@ -120,11 +124,22 @@ void FatFile::ls(print_t* pr, uint8_t flags, uint8_t indent) {
       pr->write('\r');
       pr->write('\n');
       if ((flags & LS_R) && file.isDir()) {
-        file.ls(pr, flags, indent + 2);
+        if (!file.ls(pr, flags, indent + 2)) {
+          DBG_FAIL_MACRO;
+          goto fail;
+        }
       }
     }
     file.close();
   }
+  if (getError()) {
+    DBG_FAIL_MACRO;
+    goto fail;
+  }
+  return true;
+
+ fail:
+  return false;
 }
 //------------------------------------------------------------------------------
 bool FatFile::printCreateDateTime(print_t* pr) {
diff --git a/src/FatLib/FatFileSystem.h b/src/FatLib/FatFileSystem.h
index bc72b412..044b9cf9 100644
--- a/src/FatLib/FatFileSystem.h
+++ b/src/FatLib/FatFileSystem.h
@@ -61,9 +61,11 @@ class FatFileSystem : public  FatVolume {
    * LS_SIZE - %Print file size.
    *
    * LS_R - Recursive list of subdirectories.
+   *
+   * \return true for success or false if an error occurred.
    */
-  void ls(uint8_t flags = 0) {
-    ls(&Serial, flags);
+  bool ls(uint8_t flags = 0) {
+    return ls(&Serial, flags);
   }
   /** List the directory contents of a directory to Serial.
    *
@@ -76,9 +78,11 @@ class FatFileSystem : public  FatVolume {
    * LS_SIZE - %Print file size.
    *
    * LS_R - Recursive list of subdirectories.
+   *
+   * \return true for success or false if an error occurred.
    */
-  void ls(const char* path, uint8_t flags = 0) {
-    ls(&Serial, path, flags);
+  bool ls(const char* path, uint8_t flags = 0) {
+    return ls(&Serial, path, flags);
   }
   /** open a file
    *
@@ -194,9 +198,11 @@ class FatFileSystem : public  FatVolume {
    * LS_SIZE - %Print file size.
    *
    * LS_R - Recursive list of subdirectories.
+   *
+   * \return true for success or false if an error occurred.
    */
-  void ls(print_t* pr, uint8_t flags = 0) {
-    vwd()->ls(pr, flags);
+  bool ls(print_t* pr, uint8_t flags = 0) {
+    return vwd()->ls(pr, flags);
   }
   //----------------------------------------------------------------------------
   /** List the directory contents of a directory.
@@ -212,11 +218,12 @@ class FatFileSystem : public  FatVolume {
    * LS_SIZE - %Print file size.
    *
    * LS_R - Recursive list of subdirectories.
+   *
+   * \return true for success or false if an error occurred.
    */
-  void ls(print_t* pr, const char* path, uint8_t flags) {
+  bool ls(print_t* pr, const char* path, uint8_t flags) {
     FatFile dir;
-    dir.open(vwd(), path, O_RDONLY);
-    dir.ls(pr, flags);
+    return dir.open(vwd(), path, O_RDONLY) && dir.ls(pr, flags);
   }
   //----------------------------------------------------------------------------
   /** Make a subdirectory in the volume working directory.
diff --git a/src/SdCard/SdSpiCard.cpp b/src/SdCard/SdSpiCard.cpp
index 6e20e7db..f36b59a2 100644
--- a/src/SdCard/SdSpiCard.cpp
+++ b/src/SdCard/SdSpiCard.cpp
@@ -30,10 +30,11 @@
 #define SD_CS_DBG(m)
 // #define SD_CS_DBG(m) Serial.println(F(m));
 
-#define DBG_PROFILE_TIME 0
-#if DBG_PROFILE_TIME
+#define DBG_PROFILE_STATS 0
+#if DBG_PROFILE_STATS
 
 #define DBG_TAG_LIST\
+  DBG_TAG(DBG_CMD0_TIME, "CMD0 time")\
   DBG_TAG(DBG_ACMD41_TIME, "ACMD41 time")\
   DBG_TAG(DBG_CMD_BUSY, "cmd busy")\
   DBG_TAG(DBG_ERASE_BUSY, "erase busy")\
@@ -41,7 +42,8 @@
   DBG_TAG(DBG_WRITE_FLASH, "write flash")\
   DBG_TAG(DBG_WRITE_BUSY, "write busy")\
   DBG_TAG(DBG_WRITE_STOP, "write stop")\
-  DBG_TAG(DBG_ACMD41_COUNT, "ACMD41 count")
+  DBG_TAG(DBG_ACMD41_COUNT, "ACMD41 count")\
+  DBG_TAG(DBG_CMD0_COUNT, "CMD0 count")
 
 #define DBG_TIME_DIM DBG_ACMD41_COUNT
 
@@ -62,6 +64,17 @@ static void dbgBeginTime(DbgTag tag) {
   dbgBgnTime[tag] = micros();
 }
 //------------------------------------------------------------------------------
+static void dbgClearStats() {
+  for (int i = 0; i < DBG_COUNT_DIM; i++) {
+    dbgCount[i] = 0;
+    if (i < DBG_TIME_DIM) {
+      dbgMaxTime[i] = 0;
+      dbgMinTime[i] = 9999999;
+      dbgTotalTime[i] = 0;
+    }
+  }
+}
+//------------------------------------------------------------------------------
 static void dbgEndTime(DbgTag tag) {
   uint32_t m = micros() - dbgBgnTime[tag];
   dbgTotalTime[tag] += m;
@@ -78,17 +91,6 @@ static void dbgEventCount(DbgTag tag) {
   dbgCount[tag]++;
 }
 //------------------------------------------------------------------------------
-void dbgInitTime() {
-  for (int i = 0; i < DBG_COUNT_DIM; i++) {
-    dbgCount[i] = 0;
-    if (i < DBG_TIME_DIM) {
-      dbgMaxTime[i] = 0;
-      dbgMinTime[i] = 9999999;
-      dbgTotalTime[i] = 0;
-    }
-  }
-}
-//------------------------------------------------------------------------------
 static void dbgPrintTagText(uint8_t tag) {
   #define DBG_TAG(e, m) case e: Serial.print(F(m)); break;
   switch (tag) {
@@ -97,7 +99,7 @@ static void dbgPrintTagText(uint8_t tag) {
   #undef DBG_TAG
 }
 //------------------------------------------------------------------------------
-void dbgPrintTime() {
+static void dbgPrintStats() {
   Serial.println();
   Serial.println(F("======================="));
   Serial.println(F("item,event,min,max,avg"));
@@ -125,13 +127,13 @@ void dbgPrintTime() {
 #define DBG_BEGIN_TIME(tag) dbgBeginTime(tag)
 #define DBG_END_TIME(tag) dbgEndTime(tag)
 #define DBG_EVENT_COUNT(tag) dbgEventCount(tag)
-#else  // DBG_PROFILE_TIME
+#else  // DBG_PROFILE_STATS
 #define DBG_BEGIN_TIME(tag)
 #define DBG_END_TIME(tag)
 #define DBG_EVENT_COUNT(tag)
-void dbgInitTime() {}
-void dbgPrintTime() {}
-#endif  // DBG_PROFILE_TIME
+static void dbgClearStats() {}
+static void dbgPrintStats() {}
+#endif  // DBG_PROFILE_STATS
 //==============================================================================
 #if USE_SD_CRC
 // CRC functions
@@ -242,8 +244,13 @@ bool SdSpiCard::begin(SdSpiDriver* spi, uint8_t csPin, SPISettings settings) {
   }
   spiSelect();
 
+  DBG_BEGIN_TIME(DBG_CMD0_TIME);
   // command to go idle in SPI mode
-  for (uint8_t i = 0; cardCommand(CMD0, 0) != R1_IDLE_STATE; i++) {
+  for (uint8_t i = 1;; i++) {
+    DBG_EVENT_COUNT(DBG_CMD0_COUNT);
+    if (cardCommand(CMD0, 0) == R1_IDLE_STATE) {
+      break;
+    }
     if (i == SD_CMD0_RETRY) {
       error(SD_CARD_ERROR_CMD0);
       goto fail;
@@ -255,6 +262,7 @@ bool SdSpiCard::begin(SdSpiDriver* spi, uint8_t csPin, SPISettings settings) {
       spiReceive();
     }
   }
+  DBG_END_TIME(DBG_CMD0_TIME);
 #if USE_SD_CRC
   if (cardCommand(CMD59, 1) != R1_IDLE_STATE) {
     error(SD_CARD_ERROR_CMD59);
@@ -364,6 +372,10 @@ uint32_t SdSpiCard::cardSize() {
   return readCSD(&csd) ? sdCardCapacity(&csd) : 0;
 }
 //------------------------------------------------------------------------------
+void SdSpiCard::dbgClearStats() {::dbgClearStats();}
+//------------------------------------------------------------------------------
+void SdSpiCard::dbgPrintStats() {::dbgPrintStats();}
+//------------------------------------------------------------------------------
 bool SdSpiCard::erase(uint32_t firstBlock, uint32_t lastBlock) {
   csd_t csd;
   if (!readCSD(&csd)) {
diff --git a/src/SdCard/SdSpiCard.h b/src/SdCard/SdSpiCard.h
index d8943656..bb4e83b5 100644
--- a/src/SdCard/SdSpiCard.h
+++ b/src/SdCard/SdSpiCard.h
@@ -60,6 +60,10 @@ class SdSpiCard {
    *         or zero if an error occurs.
    */
   uint32_t cardSize();
+  /** Clear debug stats. */
+  void dbgClearStats();
+  /** Print debug stats. */
+  void dbgPrintStats();
   /** Erase a range of blocks.
    *
    * \param[in] firstBlock The address of the first block in the range.
diff --git a/src/SdFat.h b/src/SdFat.h
index 9387372f..a34c8c6f 100644
--- a/src/SdFat.h
+++ b/src/SdFat.h
@@ -37,7 +37,7 @@
 #endif  // INCLUDE_SDIOS
 //------------------------------------------------------------------------------
 /** SdFat version */
-#define SD_FAT_VERSION "1.0.14"
+#define SD_FAT_VERSION "1.0.15"
 //==============================================================================
 /**
  * \class SdBaseFile
diff --git a/src/SpiDriver/SdSpiParticle.cpp b/src/SpiDriver/SdSpiParticle.cpp
index 5d1a2289..ee75bbfb 100644
--- a/src/SpiDriver/SdSpiParticle.cpp
+++ b/src/SpiDriver/SdSpiParticle.cpp
@@ -44,8 +44,7 @@ void SdSpiAltDriver::activate() {
  */
 void SdSpiAltDriver::begin(uint8_t csPin) {
   m_csPin = csPin;
-  m_spi->begin(m_csPin);
-  // Next line is redundant - begin(m_csPin) sets csPin to output mode.
+  m_spi->begin();
   pinMode(m_csPin, OUTPUT);
   digitalWrite(m_csPin, HIGH);
 }