diff --git a/demos/host/host_freertos/.cproject b/demos/host/host_freertos/.cproject
index 3db6de63c..6bc4ecf70 100644
--- a/demos/host/host_freertos/.cproject
+++ b/demos/host/host_freertos/.cproject
@@ -90,7 +90,7 @@
 					<sourceEntries>
 						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="freertos/freertos/Source/portable/GCC/ARM_CM4F"/>
 						<entry excluding="heap_2.c|heap_3.c|heap_4.c" flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name="freertos/freertos/Source/portable/MemMang"/>
-						<entry excluding="bsp/boards/embedded_artists/oem_base_board|freertos/freertoslpc/FreeRTOS_lpc43xx_m0_Tick.c|freertos/freertos/Source/portable|bsp/boards/EA4357|NGX|bsp/lpc13uxx|bsp/lpc11uxx" flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name=""/>
+						<entry excluding="bsp/lpc175x_6x|bsp/boards/embedded_artists/oem_base_board|freertos/freertoslpc/FreeRTOS_lpc43xx_m0_Tick.c|freertos/freertos/Source/portable|bsp/boards/EA4357|NGX|bsp/lpc13uxx|bsp/lpc11uxx" flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name=""/>
 					</sourceEntries>
 				</configuration>
 			</storageModule>
@@ -750,8 +750,8 @@
 					</folderInfo>
 					<sourceEntries>
 						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="freertos/freertos/Source/portable/GCC/ARM_CM4F"/>
-						<entry excluding="freertos/freertoslpc/FreeRTOS_lpc43xx_m0_Tick.c|freertos/freertos/Source/portable|bsp/boards/EA4357|NGX|bsp/lpc13uxx|bsp/lpc11uxx" flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name=""/>
 						<entry excluding="heap_2.c|heap_3.c|heap_4.c" flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name="freertos/freertos/Source/portable/MemMang"/>
+						<entry excluding="bsp/lpc175x_6x|freertos/freertoslpc/FreeRTOS_lpc43xx_m0_Tick.c|freertos/freertos/Source/portable|bsp/boards/EA4357|NGX|bsp/lpc13uxx|bsp/lpc11uxx" flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name=""/>
 					</sourceEntries>
 				</configuration>
 			</storageModule>
diff --git a/demos/host/host_freertos/app_os_prio.h b/demos/host/host_freertos/app_os_prio.h
index 25af31f6a..6a9135dfd 100644
--- a/demos/host/host_freertos/app_os_prio.h
+++ b/demos/host/host_freertos/app_os_prio.h
@@ -57,8 +57,10 @@
  extern "C" {
 #endif
 
-#define KEYBOARD_APP_TASK_PRIO     (TUSB_CFG_OS_TASK_PRIO-1)
-#define MOUSE_APP_TASK_PRIO        (KEYBOARD_APP_TASK_PRIO-1)
+#define KEYBOARD_APP_TASK_PRIO     (TUSB_CFG_OS_TASK_PRIO-2)
+#define MOUSE_APP_TASK_PRIO        KEYBOARD_APP_TASK_PRIO
+#define CDC_SERIAL_APP_TASK_PRIO   KEYBOARD_APP_TASK_PRIO
+
 #define LED_BLINKING_APP_TASK_PRIO (tskIDLE_PRIORITY+1)
 
 #ifdef __cplusplus
diff --git a/tinyusb/osal/osal_freeRTOS.h b/tinyusb/osal/osal_freeRTOS.h
index a769853c1..52883126b 100644
--- a/tinyusb/osal/osal_freeRTOS.h
+++ b/tinyusb/osal/osal_freeRTOS.h
@@ -114,6 +114,8 @@ static inline void osal_task_delay(uint32_t msec)
 #define OSAL_SUBTASK_END \
   return TUSB_ERROR_NONE;
 
+#define SUBTASK_EXIT(error)   return error;
+
 #define OSAL_SUBTASK_INVOKED_AND_WAIT(subtask, status) \
   status = subtask
 
@@ -164,6 +166,33 @@ static inline void osal_semaphore_reset(osal_semaphore_handle_t const sem_hdl)
   xSemaphoreTakeFromISR(sem_hdl, &task_waken);
 }
 
+//--------------------------------------------------------------------+
+// MUTEX API (priority inheritance)
+//--------------------------------------------------------------------+
+#define OSAL_MUTEX_DEF  OSAL_SEM_DEF
+typedef xSemaphoreHandle osal_mutex_handle_t;
+
+#define osal_mutex_create(x) \
+  xSemaphoreCreateMutex()
+
+static inline  tusb_error_t osal_mutex_release(osal_mutex_handle_t const mutex_hdl) ATTR_ALWAYS_INLINE;
+static inline  tusb_error_t osal_mutex_release(osal_mutex_handle_t const mutex_hdl)
+{
+  return (xSemaphoreGive(mutex_hdl) == pdPASS) ? TUSB_ERROR_NONE : TUSB_ERROR_OSAL_SEMAPHORE_FAILED;
+}
+
+static inline void osal_mutex_wait(osal_mutex_handle_t const mutex_hdl, uint32_t msec, tusb_error_t *p_error) ATTR_ALWAYS_INLINE;
+static inline void osal_mutex_wait(osal_mutex_handle_t const mutex_hdl, uint32_t msec, tusb_error_t *p_error)
+{
+  (*p_error) = ( xSemaphoreTake(mutex_hdl, osal_tick_from_msec(msec)) == pdPASS ) ? TUSB_ERROR_NONE : TUSB_ERROR_OSAL_TIMEOUT;
+}
+
+static inline void osal_mutex_reset(osal_mutex_handle_t const mutex_hdl) ATTR_ALWAYS_INLINE;
+static inline void osal_mutex_reset(osal_mutex_handle_t const mutex_hdl)
+{
+  xSemaphoreGive(mutex_hdl);
+}
+
 //--------------------------------------------------------------------+
 // QUEUE API
 //--------------------------------------------------------------------+