diff --git a/src/main/blackbox/blackbox.c b/src/main/blackbox/blackbox.c
index a0e3579308..d471258213 100644
--- a/src/main/blackbox/blackbox.c
+++ b/src/main/blackbox/blackbox.c
@@ -644,6 +644,9 @@ void startBlackbox(void)
     }
 }
 
+/**
+ * Begin Blackbox shutdown.
+ */
 void finishBlackbox(void)
 {
     if (blackboxState == BLACKBOX_STATE_RUNNING) {
@@ -1123,7 +1126,7 @@ void handleBlackbox(void)
              *
              * Don't wait longer than it could possibly take if something funky happens.
              */
-            if (millis() > xmitState.u.startTime + 200 || isBlackboxDeviceIdle()) {
+            if (millis() > xmitState.u.startTime + 200 || blackboxDeviceFlush()) {
                 blackboxDeviceClose();
                 blackboxSetState(BLACKBOX_STATE_STOPPED);
             }
diff --git a/src/main/blackbox/blackbox_io.c b/src/main/blackbox/blackbox_io.c
index d5eefc9c1e..acaf0f4f85 100644
--- a/src/main/blackbox/blackbox_io.c
+++ b/src/main/blackbox/blackbox_io.c
@@ -405,19 +405,24 @@ void blackboxWriteTag8_8SVB(int32_t *values, int valueCount)
 }
 
 /**
- * If there is data waiting to be written to the blackbox device, attempt to write that now.
+ * If there is data waiting to be written to the blackbox device, attempt to write (a portion of) that now.
+ * 
+ * Returns true if all data has been flushed to the device.
  */
-void blackboxDeviceFlush(void)
+bool blackboxDeviceFlush(void)
 {
     switch (masterConfig.blackbox_device) {
         case BLACKBOX_DEVICE_SERIAL:
-            //Presently a no-op on serial, as serial is continuously being drained out of its buffer
-        break;
+            //Nothing to speed up flushing on serial, as serial is continuously being drained out of its buffer
+            return isSerialTransmitBufferEmpty(blackboxPort);
+
 #ifdef USE_FLASHFS
         case BLACKBOX_DEVICE_FLASH:
-            flashfsFlushAsync();
-        break;
+            return flashfsFlushAsync();
 #endif
+
+        default:
+            return false;
     }
 }
 
@@ -470,6 +475,9 @@ bool blackboxDeviceOpen(void)
     }
 }
 
+/**
+ * Close the Blackbox logging device immediately without attempting to flush any remaining data.
+ */
 void blackboxDeviceClose(void)
 {
     switch (masterConfig.blackbox_device) {
@@ -487,27 +495,6 @@ void blackboxDeviceClose(void)
                 mspAllocateSerialPorts(&masterConfig.serialConfig);
             }
         break;
-#ifdef USE_FLASHFS
-        case BLACKBOX_DEVICE_FLASH:
-            flashfsFlushSync();
-        break;
-#endif
-    }
-}
-
-bool isBlackboxDeviceIdle(void)
-{
-    switch (masterConfig.blackbox_device) {
-        case BLACKBOX_DEVICE_SERIAL:
-            return isSerialTransmitBufferEmpty(blackboxPort);
-
-#ifdef USE_FLASHFS
-        case BLACKBOX_DEVICE_FLASH:
-            return flashfsFlushAsync();
-#endif
-
-        default:
-            return false;
     }
 }
 
diff --git a/src/main/blackbox/blackbox_io.h b/src/main/blackbox/blackbox_io.h
index 8fca16d72e..62d5909986 100644
--- a/src/main/blackbox/blackbox_io.h
+++ b/src/main/blackbox/blackbox_io.h
@@ -46,9 +46,8 @@ void blackboxWriteTag2_3S32(int32_t *values);
 void blackboxWriteTag8_4S16(int32_t *values);
 void blackboxWriteTag8_8SVB(int32_t *values, int valueCount);
 
-void blackboxDeviceFlush(void);
+bool blackboxDeviceFlush(void);
 bool blackboxDeviceOpen(void);
 void blackboxDeviceClose(void);
 
-bool isBlackboxDeviceIdle(void);
 bool isBlackboxDeviceFull(void);
diff --git a/src/main/drivers/flash_m25p16.c b/src/main/drivers/flash_m25p16.c
index e977f257ef..a6bd7b22fa 100644
--- a/src/main/drivers/flash_m25p16.c
+++ b/src/main/drivers/flash_m25p16.c
@@ -278,6 +278,11 @@ int m25p16_readBytes(uint32_t address, uint8_t *buffer, int length)
     return length;
 }
 
+/**
+ * Fetch information about the detected flash chip layout.
+ *
+ * Can be called before calling m25p16_init() (the result would have totalSize = 0).
+ */
 const flashGeometry_t* m25p16_getGeometry()
 {
     return &geometry;
diff --git a/src/main/io/flashfs.c b/src/main/io/flashfs.c
index e1de9fca6c..b271cec3ee 100644
--- a/src/main/io/flashfs.c
+++ b/src/main/io/flashfs.c
@@ -555,6 +555,7 @@ bool flashfsIsEOF() {
  */
 void flashfsInit()
 {
+    // If we have a flash chip present at all
     if (flashfsGetSize() > 0) {
         // Start the file pointer off at the beginning of free space so caller can start writing immediately
         flashfsSeekAbs(flashfsIdentifyStartOfFreeSpace());