Allow mifare to recover after usb disconnection

armsrc/iso14443a.c

@@ -37,6 +37,7 @@
 #include "desfire_crypto.h"  // UL-C authentication helpers
 #include "mifare.h"  // for iso14a_polling_frame_t structure
 #include "cmac_calc.h"
+#include "usb_cdc.h"
 
 // Forward declaration: HID Config Card jam support (implemented in secc.c).
 // Called from SniffIso14443a when param bit 0x04 is set.
@@ -2790,6 +2791,11 @@ int EmGetCmd(uint8_t *received, uint16_t received_max_len, uint16_t *len, uint8_
                 return 1;
             }
 
+            // Keep USB enumeration alive while this real-time loop waits for RF.
+            if (Uart.state == STATE_14A_UNSYNCD) {
+                usb_check();
+            }
+
             flip++;
             checker = 4000;
         }