Merge pull request #9089 from jflyper/bfdev-serial-blackbox-handle-bu…

…ffer-overflow-properly Serial blackbox: check TX buffer space before calling serialWrite
betaflight · Oct 27, 2019 · 1d9fff5 · 1d9fff5
1 parent db062d7
commit 1d9fff5
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/src/main/blackbox/blackbox_io.c b/src/main/blackbox/blackbox_io.c
@@ -102,7 +102,14 @@ void blackboxWrite(uint8_t value)
 #endif
     case BLACKBOX_DEVICE_SERIAL:
     default:
-        serialWrite(blackboxPort, value);
+        {
+            int txBytesFree = serialTxBytesFree(blackboxPort);
+
+            if (txBytesFree == 0) {
+                return;
+            }
+            serialWrite(blackboxPort, value);
+        }
         break;
     }
 }
@@ -133,7 +140,7 @@ int blackboxWriteString(const char *s)
     default:
         pos = (uint8_t*) s;
         while (*pos) {
-            serialWrite(blackboxPort, *pos);
+            blackboxWrite(*pos);
             pos++;
         }