Avoid synchronous flushes to flash during Blackbox shutdown

src/main/blackbox/blackbox_io.c

@@ -415,7 +415,7 @@ void blackboxDeviceFlush(void)
         break;
 #ifdef USE_FLASHFS
         case BLACKBOX_DEVICE_FLASH:
-            flashfsFlushSync();
+            flashfsFlushAsync();
         break;
 #endif
     }
@@ -503,8 +503,7 @@ bool isBlackboxDeviceIdle(void)
 
 #ifdef USE_FLASHFS
         case BLACKBOX_DEVICE_FLASH:
-            flashfsFlushSync();
-            return true;
+            return flashfsFlushAsync();
 #endif
 
         default:

src/main/io/flashfs.c

@@ -295,12 +295,14 @@ static void flashfsAdvanceTailInBuffer(uint32_t delta)
 /**
  * If the flash is ready to accept writes, flush the buffer to it, otherwise schedule
  * a flush for later and return immediately.
+ *
+ * Returns true if all data in the buffer has been flushed to the device.
  */
-void flashfsFlushAsync()
+bool flashfsFlushAsync()
 {
     if (flashfsBufferIsEmpty()) {
         shouldFlush = false;
-        return; // Nothing to flush
+        return true; // Nothing to flush
     }
 
     uint8_t const * buffers[2];
@@ -312,6 +314,8 @@ void flashfsFlushAsync()
     flashfsAdvanceTailInBuffer(bytesWritten);
 
     shouldFlush = !flashfsBufferIsEmpty();
+
+    return flashfsBufferIsEmpty();
 }
 
 /**

src/main/io/flashfs.h

@@ -43,7 +43,7 @@ void flashfsWrite(const uint8_t *data, unsigned int len, bool sync);
 
 int flashfsReadAbs(uint32_t offset, uint8_t *data, unsigned int len);
 
-void flashfsFlushAsync();
+bool flashfsFlushAsync();
 void flashfsFlushSync();
 
 void flashfsInit();

src/main/io/serial_cli.c

@@ -772,7 +772,12 @@ static void cliFlashErase(char *cmdline)
 
     printf("Erasing, please wait...\r\n");
     flashfsEraseCompletely();
-    printf("Erased flash chip.\r\n");
+
+    while (!flashfsIsReady()) {
+        delay(100);
+    }
+
+    printf("Done.\r\n");
 }
 
 static void cliFlashWrite(char *cmdline)

src/main/main.c

@@ -52,7 +52,6 @@
 
 #include "io/serial.h"
 #include "io/flashfs.h"
-
 #include "io/gps.h"
 #include "io/escservo.h"
 #include "io/rc_controls.h"