diff --git a/src/osal/osal_rtthread.h b/src/osal/osal_rtthread.h
index a790a5e2..f8452bfb 100644
--- a/src/osal/osal_rtthread.h
+++ b/src/osal/osal_rtthread.h
@@ -49,7 +49,7 @@ typedef rt_sem_t osal_semaphore_t;
 
 TU_ATTR_ALWAYS_INLINE static inline osal_semaphore_t
 osal_semaphore_create(osal_semaphore_def_t *semdef) {
-    rt_sem_init(semdef, "tusb", 0, RT_IPC_FLAG_FIFO);
+    rt_sem_init(semdef, "tusb", 0, RT_IPC_FLAG_PRIO);
     return semdef;
 }
 
@@ -59,7 +59,7 @@ TU_ATTR_ALWAYS_INLINE static inline bool osal_semaphore_post(osal_semaphore_t se
 }
 
 TU_ATTR_ALWAYS_INLINE static inline bool osal_semaphore_wait(osal_semaphore_t sem_hdl, uint32_t msec) {
-    return rt_sem_take(sem_hdl, rt_tick_from_millisecond(msec)) == RT_EOK;
+    return rt_sem_take(sem_hdl, rt_tick_from_millisecond((rt_int32_t) msec)) == RT_EOK;
 }
 
 TU_ATTR_ALWAYS_INLINE static inline void osal_semaphore_reset(osal_semaphore_t const sem_hdl) {
@@ -73,12 +73,12 @@ typedef struct rt_mutex osal_mutex_def_t;
 typedef rt_mutex_t osal_mutex_t;
 
 TU_ATTR_ALWAYS_INLINE static inline osal_mutex_t osal_mutex_create(osal_mutex_def_t *mdef) {
-    rt_mutex_init(mdef, "tusb", RT_IPC_FLAG_FIFO);
+    rt_mutex_init(mdef, "tusb", RT_IPC_FLAG_PRIO);
     return mdef;
 }
 
 TU_ATTR_ALWAYS_INLINE static inline bool osal_mutex_lock(osal_mutex_t mutex_hdl, uint32_t msec) {
-    return rt_mutex_take(mutex_hdl, rt_tick_from_millisecond(msec)) == RT_EOK;
+    return rt_mutex_take(mutex_hdl, rt_tick_from_millisecond((rt_int32_t) msec)) == RT_EOK;
 }
 
 TU_ATTR_ALWAYS_INLINE static inline bool osal_mutex_unlock(osal_mutex_t mutex_hdl) {
@@ -106,13 +106,13 @@ typedef rt_mq_t osal_queue_t;
 
 TU_ATTR_ALWAYS_INLINE static inline osal_queue_t osal_queue_create(osal_queue_def_t *qdef) {
     rt_mq_init(&(qdef->sq), "tusb", qdef->buf, qdef->item_sz,
-               qdef->item_sz * qdef->depth, RT_IPC_FLAG_FIFO);
+               qdef->item_sz * qdef->depth, RT_IPC_FLAG_PRIO);
     return &(qdef->sq);
 }
 
 TU_ATTR_ALWAYS_INLINE static inline bool osal_queue_receive(osal_queue_t qhdl, void *data, uint32_t msec) {
 
-    rt_tick_t tick = rt_tick_from_millisecond((rt_int32_t) msec));
+    rt_tick_t tick = rt_tick_from_millisecond((rt_int32_t) msec);
     return rt_mq_recv(qhdl, data, qhdl->msg_size, tick) == RT_EOK;
 }