🩹 Fix linker error (transfer_port_index)

3 years ago · 5a0166489e
1 changed files with 2 additions and 2 deletions
--- a/Marlin/src/sd/cardreader.cpp
+++ b/Marlin/src/sd/cardreader.cpp
@ -72,8 +72,8 @@ char CardReader::filename[FILENAME_LENGTH], CardReader::longFilename[LONG_FILENA

 IF_DISABLED(NO_SD_AUTOSTART, uint8_t CardReader::autofile_index); // = 0

-#if BOTH(HAS_MULTI_SERIAL, BINARY_FILE_TRANSFER)
-  serial_index_t CardReader::transfer_port_index;
+#if ENABLED(BINARY_FILE_TRANSFER)
+  serial_index_t IF_DISABLED(HAS_MULTI_SERIAL, constexpr) CardReader::transfer_port_index;
 #endif

 // private: