diff --git a/arch/arm/src/lc823450/lc823450_usbdev.c b/arch/arm/src/lc823450/lc823450_usbdev.c
index facacbc43c..7929c9195f 100644
--- a/arch/arm/src/lc823450/lc823450_usbdev.c
+++ b/arch/arm/src/lc823450/lc823450_usbdev.c
@@ -122,6 +122,7 @@ struct lc823450_usbdev_s
   struct usbdev_s             usbdev;
   struct usbdevclass_driver_s *driver;
   struct lc823450_ep_s        eplist[LC823450_NPHYSENDPOINTS];
+  spinlock_t                  lock;         /* Spinlock */
   int                         bufoffset;
   uint8_t                     used;         /* used phyep */
 #ifdef CONFIG_WAKELOCK
@@ -477,7 +478,7 @@ static int lc823450_epclearreq(struct usbdev_ep_s *ep)
   struct lc823450_ep_s *privep = (struct lc823450_ep_s *)ep;
   irqstate_t flags;
 
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
   while (privep->req_q.tail)
     {
       struct usbdev_req_s *req;
@@ -494,7 +495,7 @@ static int lc823450_epclearreq(struct usbdev_ep_s *ep)
       req->callback(ep, req);
     }
 
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
   return 0;
 }
 
@@ -659,27 +660,27 @@ static int lc823450_epsubmit(struct usbdev_ep_s *ep,
 
   if (privep->epphy == 0)
     {
-      flags = spin_lock_irqsave(NULL);
+      flags = spin_lock_irqsave(&g_usbdev.lock);
       req->xfrd = epbuf_write(privep->epphy, req->buf, req->len);
-      spin_unlock_irqrestore(NULL, flags);
+      spin_unlock_irqrestore(&g_usbdev.lock, flags);
       req->callback(ep, req);
     }
   else if (privep->in)
     {
       /* Send packet request from function driver */
 
-      flags = spin_lock_irqsave(NULL);
+      flags = spin_lock_irqsave(&g_usbdev.lock);
 
       if ((getreg32(USB_EPCOUNT(privep->epphy * 2)) &
           USB_EPCOUNT_PHYCNT_MASK) >> USB_EPCOUNT_PHYCNT_SHIFT ||
           privep->req_q.tail)
         {
           sq_addfirst(&privreq->q_ent, &privep->req_q); /* non block */
-          spin_unlock_irqrestore(NULL, flags);
+          spin_unlock_irqrestore(&g_usbdev.lock, flags);
         }
        else
         {
-          spin_unlock_irqrestore(NULL, flags);
+          spin_unlock_irqrestore(&g_usbdev.lock, flags);
           req->xfrd = epbuf_write(privep->epphy, req->buf, req->len);
           req->callback(ep, req);
         }
@@ -688,9 +689,9 @@ static int lc823450_epsubmit(struct usbdev_ep_s *ep,
     {
       /* receive packet buffer from function driver */
 
-      flags = spin_lock_irqsave(NULL);
+      flags = spin_lock_irqsave(&g_usbdev.lock);
       sq_addfirst(&privreq->q_ent, &privep->req_q); /* non block */
-      spin_unlock_irqrestore(NULL, flags);
+      spin_unlock_irqrestore(&g_usbdev.lock, flags);
       lc823450_epack(privep->epphy, 1);
     }
 
@@ -714,9 +715,9 @@ static int lc823450_epcancel(struct usbdev_ep_s *ep,
 
   /* Remove request from req_queue */
 
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
   sq_remafter(&privreq->q_ent, &privep->req_q);
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
   return 0;
 }
 
@@ -735,7 +736,7 @@ static int lc823450_epstall(struct usbdev_ep_s *ep, bool resume)
 
   /* STALL or RESUME the endpoint */
 
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
   usbtrace(resume ? TRACE_EPRESUME : TRACE_EPSTALL, privep->epphy);
 
   if (resume)
@@ -749,7 +750,7 @@ static int lc823450_epstall(struct usbdev_ep_s *ep, bool resume)
       epcmd_write(privep->epphy, USB_EPCMD_STALL_SET | USB_EPCMD_TGL_SET);
     }
 
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
   return OK;
 }
 
@@ -758,11 +759,11 @@ void up_epignore_clear_stall(struct usbdev_ep_s *ep, bool ignore)
 {
   struct lc823450_ep_s *privep = (struct lc823450_ep_s *)ep;
   irqstate_t flags;
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
 
   privep->ignore_clear_stall = ignore;
 
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
 }
 #endif /* CONFIG_USBMSC_IGNORE_CLEAR_STALL */
 
@@ -919,7 +920,7 @@ static void usb_suspend_work_func(void *arg)
     }
 #endif
 
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
   if (getreg32(USB_DEVS) & USB_DEVS_SUSPEND)
     {
       uinfo("USB BUS SUSPEND\n");
@@ -934,7 +935,7 @@ static void usb_suspend_work_func(void *arg)
       wake_unlock(&priv->wlock);
     }
 
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
 }
 #endif
 
@@ -1252,7 +1253,7 @@ static void subintr_epin(uint8_t epnum, struct lc823450_ep_s *privep)
   /* Send packet done */
 
   irqstate_t flags;
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
 
   if (privep->req_q.tail)
     {
@@ -1263,7 +1264,7 @@ static void subintr_epin(uint8_t epnum, struct lc823450_ep_s *privep)
 
       q_ent = sq_remlast(&privep->req_q);
 
-      spin_unlock_irqrestore(NULL, flags);
+      spin_unlock_irqrestore(&g_usbdev.lock, flags);
 
       req = &container_of(q_ent, struct lc823450_req_s, q_ent)->req;
 
@@ -1279,7 +1280,7 @@ static void subintr_epin(uint8_t epnum, struct lc823450_ep_s *privep)
     }
   else
     {
-      spin_unlock_irqrestore(NULL, flags);
+      spin_unlock_irqrestore(&g_usbdev.lock, flags);
       epcmd_write(epnum, USB_EPCMD_EMPTY_CLR);
     }
 }
@@ -1297,7 +1298,7 @@ static void subintr_epout(uint8_t epnum, struct lc823450_ep_s *privep)
   /* Packet receive from host */
 
   irqstate_t flags;
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
 
   if (privep->req_q.tail)
     {
@@ -1316,7 +1317,7 @@ static void subintr_epout(uint8_t epnum, struct lc823450_ep_s *privep)
           lc823450_epack(epnum, 0);
         }
 
-      spin_unlock_irqrestore(NULL, flags);
+      spin_unlock_irqrestore(&g_usbdev.lock, flags);
 
       /* PIO */
 
@@ -1329,7 +1330,7 @@ static void subintr_epout(uint8_t epnum, struct lc823450_ep_s *privep)
     }
   else
     {
-      spin_unlock_irqrestore(NULL, flags);
+      spin_unlock_irqrestore(&g_usbdev.lock, flags);
       uinfo("REQ Buffer Exhault\n");
       epcmd_write(epnum, USB_EPCMD_READY_CLR);
     }
@@ -1430,6 +1431,7 @@ void arm_usbinitialize(void)
   memset(&g_usbdev, 0, sizeof(g_usbdev));
   g_usbdev.usbdev.ops = &g_devops;
   g_usbdev.usbdev.ep0 = &g_usbdev.eplist[0].ep;
+  spin_lock_init(&g_usbdev.lock);
 
   for (i = 0; i < LC823450_NPHYSENDPOINTS; i++)
     {
@@ -1647,7 +1649,7 @@ int usbdev_unregister(struct usbdevclass_driver_s *driver)
    * canceled while the class driver is still bound.
    */
 
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
 
 #ifdef CONFIG_WAKELOCK
   /* cancel USB suspend work */
@@ -1683,7 +1685,7 @@ int usbdev_unregister(struct usbdevclass_driver_s *driver)
   pm_unregister(&g_pm_cb);
 #endif /* CONFIG_PM */
 
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
 
 #ifdef CONFIG_LC823450_LSISTBY
   /* disable USB */
@@ -1933,7 +1935,7 @@ static void usbdev_pmnotify(struct pm_callback_s *cb,
 {
   irqstate_t flags;
 
-  flags = spin_lock_irqsave(NULL);
+  flags = spin_lock_irqsave(&g_usbdev.lock);
 
   switch (pmstate)
     {
@@ -1956,6 +1958,6 @@ static void usbdev_pmnotify(struct pm_callback_s *cb,
         break;
     }
 
-  spin_unlock_irqrestore(NULL, flags);
+  spin_unlock_irqrestore(&g_usbdev.lock, flags);
 }
 #endif