diff --git a/ChibiOS b/ChibiOS
index ade76de..0cfe7f5 160000
--- a/ChibiOS
+++ b/ChibiOS
@@ -1 +1 @@
-Subproject commit ade76dea89cd093650552328e881252a06486094
+Subproject commit 0cfe7f528599d634c7e77b27984b24b9ad0c4d4c
diff --git a/halconf.h b/halconf.h
index 5ea5b6e..e8d80b9 100644
--- a/halconf.h
+++ b/halconf.h
@@ -302,11 +302,14 @@
  * @brief   Serial buffers size.
  * @details Configuration parameter, you can change the depth of the queue
  *          buffers depending on the requirements of your application.
- * @note    The default is 64 bytes for both the transmission and receive
+ * @note    The default is 16 bytes for both the transmission and receive
  *          buffers.
  */
-#if !defined(SERIAL_BUFFERS_SIZE) || defined(__DOXYGEN__)
-#define SERIAL_BUFFERS_SIZE         64
+#if !defined(SERIAL_RX_BUFFERS_SIZE) || defined(__DOXYGEN__)
+#define SERIAL_RX_BUFFERS_SIZE      16
+#endif
+#if !defined(SERIAL_TX_BUFFERS_SIZE) || defined(__DOXYGEN__)
+#define SERIAL_TX_BUFFERS_SIZE      16
 #endif
 
 /*===========================================================================*/
@@ -317,23 +320,25 @@
  * @brief   Serial over USB buffers size.
  * @details Configuration parameter, the buffer size must be a multiple of
  *          the USB data endpoint maximum packet size.
- * @note    The default is 64 bytes for both the transmission and receive
+ * @note    The default is 256 bytes for both the transmission and receive
  *          buffers.
  */
-#if !defined(SERIAL_USB_BUFFERS_SIZE) || defined(__DOXYGEN__)
-#ifdef TINYSA4
-#define SERIAL_USB_BUFFERS_SIZE     128
-#else
-#define SERIAL_USB_BUFFERS_SIZE     128
+#if !defined(SERIAL_USB_RX_BUFFERS_SIZE) || defined(__DOXYGEN__)
+#define SERIAL_USB_RX_BUFFERS_SIZE  256
 #endif
+#if !defined(SERIAL_USB_TX_BUFFERS_SIZE) || defined(__DOXYGEN__)
+#define SERIAL_USB_TX_BUFFERS_SIZE  256
 #endif
 
 /**
  * @brief   Serial over USB number of buffers.
  * @note    The default is 2 buffers.
  */
-#if !defined(SERIAL_USB_BUFFERS_NUMBER) || defined(__DOXYGEN__)
-#define SERIAL_USB_BUFFERS_NUMBER   2
+#if !defined(SERIAL_USB_RX_BUFFERS_NUMBER) || defined(__DOXYGEN__)
+#define SERIAL_USB_RX_BUFFERS_NUMBER 2
+#endif
+#if !defined(SERIAL_USB_TX_BUFFERS_NUMBER) || defined(__DOXYGEN__)
+#define SERIAL_USB_TX_BUFFERS_NUMBER 2
 #endif
 
 /*===========================================================================*/
diff --git a/main.c b/main.c
index 0f3948c..1ca930e 100644
--- a/main.c
+++ b/main.c
@@ -2708,6 +2708,7 @@ void shell_update_speed(void){
 }
 
 void shell_reset_console(void){
+  osalSysLock();                           // I-class calls below, must run locked
   // Reset I/O queue over USB (for USB need also connect/disconnect)
   if (usb_IsActive()){
     if (config._mode & _MODE_SERIAL)
@@ -2720,7 +2721,8 @@ void shell_reset_console(void){
 //  iqResetI(&SD1.iqueue);
   qResetI(&SD1.oqueue);
   qResetI(&SD1.iqueue);
-
+  osalOsRescheduleS();
+  osalSysUnlock();
 }
 
 
@@ -2901,7 +2903,12 @@ static void VNAShell_executeLine(char *line)
         int timeout_count = 0;
         msg_t result;
         do {
-          result = osalThreadEnqueueTimeoutS(&shell_thread, MS2ST(5000));  // 5 second timeout
+          chSysLock();                          // S-class call, must run locked
+          if (shell_function)
+            result = osalThreadEnqueueTimeoutS(&shell_thread, MS2ST(5000));  // 5 second timeout
+          else
+            result = MSG_OK;
+          chSysUnlock();
           if (result == MSG_TIMEOUT) {
             timeout_count++;
             if (timeout_count > 3) {
diff --git a/ui.c b/ui.c
index 643472e..6ca1266 100644
--- a/ui.c
+++ b/ui.c
@@ -269,13 +269,13 @@ static int btn_wait_release(void)
     }
 
     if (dt > BUTTON_DOWN_LONG_TICKS &&
-      ticks > last_button_repeat_ticks) {
+      ticks - last_button_repeat_ticks > BUTTON_REPEAT_TICKS) {  // elapsed time, wrap safe
       int status = 0;
       if (cur_button & (1<<BIT_DOWN1))
         status |= (config.flip ? EVT_UP: EVT_DOWN) | EVT_REPEAT;
       if (cur_button & (1<<BIT_UP1))
         status |= (config.flip ? EVT_DOWN:EVT_UP) | EVT_REPEAT;
-      last_button_repeat_ticks = ticks + BUTTON_REPEAT_TICKS;
+      last_button_repeat_ticks = ticks;
       return status;
     }
   }