diff --git a/components/drivers/Kconfig b/components/drivers/Kconfig
index 6b57ff00c3a43b77d4d7d4f5b2946ca06d1ed98d..c2e6d3a411e9da4310d84177c7c2d7d100198b79 100755
--- a/components/drivers/Kconfig
+++ b/components/drivers/Kconfig
@@ -125,7 +125,6 @@ config RT_USING_PM
 
 config RT_USING_RTC
     bool "Using RTC device drivers"
-    select RT_USING_LIBC
     default n
 
     if RT_USING_RTC
diff --git a/components/drivers/usb/usbdevice/class/rndis.c b/components/drivers/usb/usbdevice/class/rndis.c
index ec61234947439314be5651ec3542785ce9e16e46..93e0ba6ae212de1ea4570690c40f80582d3984d0 100644
--- a/components/drivers/usb/usbdevice/class/rndis.c
+++ b/components/drivers/usb/usbdevice/class/rndis.c
@@ -421,7 +421,7 @@ static rt_err_t _rndis_query_response(ufunction_t func,rndis_query_msg_t msg)
     case OID_GEN_LINK_SPEED:
         resp = _create_resp(4);
         if(resp == RT_NULL) break;
-        _set_resp(resp, func->device->dcd->device_is_hs ? (480UL * 1000 *1000) : (12UL * 1000 * 1000) / 100);
+        _set_resp(resp, (func->device->dcd->device_is_hs ? (480UL * 1000 *1000) : (12UL * 1000 * 1000)) / 100);
         break;
 
     case OID_GEN_MEDIA_CONNECT_STATUS:
diff --git a/components/utilities/Kconfig b/components/utilities/Kconfig
index 250239aea60d25c94126f67236a1f5667a0a2891..9a5051298997028c23d3575d5001308571154aca 100644
--- a/components/utilities/Kconfig
+++ b/components/utilities/Kconfig
@@ -146,7 +146,6 @@ config RT_USING_ULOG
             config ULOG_TIME_USING_TIMESTAMP
                 bool "Enable timestamp format for time."
                 default n
-                select RT_USING_LIBC
                 depends on ULOG_OUTPUT_TIME
 
             config ULOG_OUTPUT_LEVEL
diff --git a/src/thread.c b/src/thread.c
index bee5f0c2c0c84b5de93bd22649c95be3e5052d6b..c5f75a11760f993fddb991dacec584313e64e567 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -107,11 +107,11 @@ void rt_thread_exit(void)
         rt_list_insert_after(&rt_thread_defunct, &(thread->tlist));
     }
 
-    /* enable interrupt */
-    rt_hw_interrupt_enable(level);
-
     /* switch to next task */
     rt_schedule();
+
+    /* enable interrupt */
+    rt_hw_interrupt_enable(level);
 }
 
 static rt_err_t _rt_thread_init(struct rt_thread *thread,