diff --git a/src/class/midi/midi_device.c b/src/class/midi/midi_device.c
index 4eac0de48..c39e03976 100644
--- a/src/class/midi/midi_device.c
+++ b/src/class/midi/midi_device.c
@@ -240,15 +240,15 @@ uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, uint8_t const*
 
   midid_stream_t* stream = &midi->stream_write;
 
-  uint32_t total_written = 0;
   uint32_t i = 0;
-  while ( i < bufsize )
+  while ( (i < bufsize) && (tu_fifo_remaining(&midi->tx_ff) >= 4) )
   {
     uint8_t const data = buffer[i];
+    i++;
 
     if ( stream->index == 0 )
     {
-      // new event packet
+      //------------- New event packet -------------//
 
       uint8_t const msg = data >> 4;
 
@@ -310,9 +310,9 @@ uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, uint8_t const*
     }
     else
     {
-      // On-going (buffering) packet
+      //------------- On-going (buffering) packet -------------//
 
-      TU_ASSERT(stream->index < 4, total_written);
+      TU_ASSERT(stream->index < 4, i);
       stream->buffer[stream->index] = data;
       stream->index++;
 
@@ -335,19 +335,14 @@ uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, uint8_t const*
       // complete current event packet, reset stream
       stream->index = stream->total = 0;
 
-      // fifo overflow, here we assume FIFO is multiple of 4 and didn't check remaining before writing
-      if ( count != 4 ) break;
-
-      // updated written if succeeded
-      total_written = i;
+      // FIFO overflown, since we already check fifo remaining. It is probably race condition
+      TU_ASSERT(count == 4, i);
     }
-
-    i++;
   }
 
   write_flush(midi);
 
-  return total_written;
+  return i;
 }
 
 bool tud_midi_n_packet_write (uint8_t itf, uint8_t const packet[4])
diff --git a/src/class/msc/msc_device.c b/src/class/msc/msc_device.c
index 7f13b4891..014e8b69e 100644
--- a/src/class/msc/msc_device.c
+++ b/src/class/msc/msc_device.c
@@ -37,6 +37,10 @@
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
+
+// Can be selectively disabled to reduce logging when troubleshooting other driver
+#define MSC_DEBUG   2
+
 enum
 {
   MSC_STAGE_CMD  = 0,
@@ -99,7 +103,7 @@ static inline uint16_t rdwr10_get_blockcount(uint8_t const command[])
 //--------------------------------------------------------------------+
 #if CFG_TUSB_DEBUG >= 2
 
-static tu_lookup_entry_t const _msc_scsi_cmd_lookup[] =
+TU_ATTR_UNUSED static tu_lookup_entry_t const _msc_scsi_cmd_lookup[] =
 {
   { .key = SCSI_CMD_TEST_UNIT_READY              , .data = "Test Unit Ready" },
   { .key = SCSI_CMD_INQUIRY                      , .data = "Inquiry" },
@@ -114,7 +118,7 @@ static tu_lookup_entry_t const _msc_scsi_cmd_lookup[] =
   { .key = SCSI_CMD_WRITE_10                     , .data = "Write10" }
 };
 
-static tu_lookup_table_t const _msc_scsi_cmd_table =
+TU_ATTR_UNUSED static tu_lookup_table_t const _msc_scsi_cmd_table =
 {
   .count = TU_ARRAY_SIZE(_msc_scsi_cmd_lookup),
   .items = _msc_scsi_cmd_lookup
@@ -232,8 +236,8 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
       TU_ASSERT( event == XFER_RESULT_SUCCESS &&
                  xferred_bytes == sizeof(msc_cbw_t) && p_cbw->signature == MSC_CBW_SIGNATURE );
 
-      TU_LOG2("  SCSI Command: %s\r\n", tu_lookup_find(&_msc_scsi_cmd_table, p_cbw->command[0]));
-      // TU_LOG2_MEM(p_cbw, xferred_bytes, 2);
+      TU_LOG(MSC_DEBUG, "  SCSI Command: %s\r\n", tu_lookup_find(&_msc_scsi_cmd_table, p_cbw->command[0]));
+      // TU_LOG_MEM(MSC_DEBUG, p_cbw, xferred_bytes, 2);
 
       p_csw->signature    = MSC_CSW_SIGNATURE;
       p_csw->tag          = p_cbw->tag;
@@ -305,8 +309,8 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
     break;
 
     case MSC_STAGE_DATA:
-      TU_LOG2("  SCSI Data\r\n");
-      //TU_LOG2_MEM(_mscd_buf, xferred_bytes, 2);
+      TU_LOG(MSC_DEBUG, "  SCSI Data\r\n");
+      //TU_LOG_MEM(MSC_DEBUG, _mscd_buf, xferred_bytes, 2);
 
       // OUT transfer, invoke callback if needed
       if ( !tu_bit_test(p_cbw->dir, 7) )
@@ -402,8 +406,8 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
       // Wait for the Status phase to complete
       if( (ep_addr == p_msc->ep_in) && (xferred_bytes == sizeof(msc_csw_t)) )
       {
-        TU_LOG2("  SCSI Status: %u\r\n", p_csw->status);
-        // TU_LOG2_MEM(p_csw, xferred_bytes, 2);
+        TU_LOG(MSC_DEBUG, "  SCSI Status: %u\r\n", p_csw->status);
+        // TU_LOG_MEM(MSC_DEBUG, p_csw, xferred_bytes, 2);
 
         // Invoke complete callback if defined
         // Note: There is racing issue with samd51 + qspi flash testing with arduino
diff --git a/src/common/tusb_common.h b/src/common/tusb_common.h
index 8490daad7..c8a66a879 100644
--- a/src/common/tusb_common.h
+++ b/src/common/tusb_common.h
@@ -305,11 +305,11 @@ void tu_print_var(uint8_t const* buf, uint32_t bufsize)
 }
 
 // Log with Level
-#define TU_LOG(n, ...)        TU_LOG##n(__VA_ARGS__)
-#define TU_LOG_MEM(n, ...)    TU_LOG##n##_MEM(__VA_ARGS__)
-#define TU_LOG_VAR(n, ...)    TU_LOG##n##_VAR(__VA_ARGS__)
-#define TU_LOG_INT(n, ...)    TU_LOG##n##_INT(__VA_ARGS__)
-#define TU_LOG_HEX(n, ...)    TU_LOG##n##_HEX(__VA_ARGS__)
+#define TU_LOG(n, ...)        TU_XSTRCAT(TU_LOG, n)(__VA_ARGS__)
+#define TU_LOG_MEM(n, ...)    TU_XSTRCAT3(TU_LOG, n, _MEM)(__VA_ARGS__)
+#define TU_LOG_VAR(n, ...)    TU_XSTRCAT3(TU_LOG, n, _VAR)(__VA_ARGS__)
+#define TU_LOG_INT(n, ...)    TU_XSTRCAT3(TU_LOG, n, _INT)(__VA_ARGS__)
+#define TU_LOG_HEX(n, ...)    TU_XSTRCAT3(TU_LOG, n, _HEX)(__VA_ARGS__)
 #define TU_LOG_LOCATION()     tu_printf("%s: %d:\r\n", __PRETTY_FUNCTION__, __LINE__)
 #define TU_LOG_FAILED()       tu_printf("%s: %d: Failed\r\n", __PRETTY_FUNCTION__, __LINE__)
 
@@ -373,6 +373,14 @@ static inline const char* tu_lookup_find(tu_lookup_table_t const* p_table, uint3
 #endif
 
 // TODO replace all TU_LOGn with TU_LOG(n)
+
+#define TU_LOG0(...)
+#define TU_LOG0_MEM(...)
+#define TU_LOG0_VAR(...)
+#define TU_LOG0_INT(...)
+#define TU_LOG0_HEX(...)
+
+
 #ifndef TU_LOG1
   #define TU_LOG1(...)
   #define TU_LOG1_MEM(...)
diff --git a/src/common/tusb_compiler.h b/src/common/tusb_compiler.h
index f755e13f4..0dd9ba016 100644
--- a/src/common/tusb_compiler.h
+++ b/src/common/tusb_compiler.h
@@ -32,10 +32,14 @@
 #ifndef _TUSB_COMPILER_H_
 #define _TUSB_COMPILER_H_
 
-#define TU_STRING(x)      #x              ///< stringify without expand
-#define TU_XSTRING(x)     TU_STRING(x)    ///< expand then stringify
-#define TU_STRCAT(a, b)   a##b            ///< concat without expand
-#define TU_XSTRCAT(a, b)  TU_STRCAT(a, b) ///< expand then concat
+#define TU_STRING(x)          #x                  ///< stringify without expand
+#define TU_XSTRING(x)         TU_STRING(x)        ///< expand then stringify
+
+#define TU_STRCAT(a, b)       a##b                ///< concat without expand
+#define TU_STRCAT3(a, b, c)   a##b##c             ///< concat without expand
+
+#define TU_XSTRCAT(a, b)      TU_STRCAT(a, b)     ///< expand then concat
+#define TU_XSTRCAT3(a, b, c)  TU_STRCAT3(a, b, c) ///< expand then concat 3 tokens
 
 #if defined __COUNTER__ && __COUNTER__ != __COUNTER__
   #define _TU_COUNTER_ __COUNTER__
diff --git a/src/common/tusb_fifo.h b/src/common/tusb_fifo.h
index de2ae163d..18db289a1 100644
--- a/src/common/tusb_fifo.h
+++ b/src/common/tusb_fifo.h
@@ -120,9 +120,9 @@ bool     tu_fifo_peek                   (tu_fifo_t* f, void * p_buffer);
 uint16_t tu_fifo_peek_n                 (tu_fifo_t* f, void * p_buffer, uint16_t n);
 
 uint16_t tu_fifo_count                  (tu_fifo_t* f);
+uint16_t tu_fifo_remaining              (tu_fifo_t* f);
 bool     tu_fifo_empty                  (tu_fifo_t* f);
 bool     tu_fifo_full                   (tu_fifo_t* f);
-uint16_t tu_fifo_remaining              (tu_fifo_t* f);
 bool     tu_fifo_overflowed             (tu_fifo_t* f);
 void     tu_fifo_correct_read_pointer   (tu_fifo_t* f);