diff --git a/components/drivers/i2c/i2c-bit-ops.c b/components/drivers/i2c/i2c-bit-ops.c
index 0d82d55fd404e758cc0492c1552b2f91ea49c8a6..d4a26ea72a83dc4eee4b057f197dcfb9818b7ac1 100644
--- a/components/drivers/i2c/i2c-bit-ops.c
+++ b/components/drivers/i2c/i2c-bit-ops.c
@@ -451,9 +451,6 @@ static const struct rt_i2c_bus_device_ops i2c_bit_bus_ops =
 rt_err_t rt_i2c_bit_add_bus(struct rt_i2c_bus_device *bus,
                             const char               *bus_name)
 {
-    struct rt_i2c_bit_ops *bit_ops = bus->priv;
-    RT_ASSERT(bit_ops != RT_NULL);
-
     bus->ops = &i2c_bit_bus_ops;
 
     return rt_i2c_bus_device_register(bus, bus_name);
diff --git a/components/drivers/i2c/i2c_dev.c b/components/drivers/i2c/i2c_dev.c
index cce53d5c92da065a52d8083b022546ab03404417..4b811c62ea9338d76c2f22dbe8a0fe1977f7f84a 100644
--- a/components/drivers/i2c/i2c_dev.c
+++ b/components/drivers/i2c/i2c_dev.c
@@ -20,18 +20,11 @@
  * Change Logs:
  * Date           Author        Notes
  * 2012-04-25     weety         first version
+ * 2014-08-03     bernard       fix some compiling warning
  */
 
 #include <rtdevice.h>
 
-static rt_err_t i2c_bus_device_init(rt_device_t dev)
-{
-    struct rt_i2c_bus_device *bus = (struct rt_i2c_bus_device *)dev->user_data;
-    RT_ASSERT(bus != RT_NULL);
-
-    return RT_EOK;
-}
-
 static rt_size_t i2c_bus_device_read(rt_device_t dev,
                                      rt_off_t    pos,
                                      void       *buffer,
@@ -122,7 +115,7 @@ rt_err_t rt_i2c_bus_device_device_init(struct rt_i2c_bus_device *bus,
     /* set device type */
     device->type    = RT_Device_Class_I2CBUS;
     /* initialize device interface */
-    device->init    = i2c_bus_device_init;
+    device->init    = RT_NULL;
     device->open    = RT_NULL;
     device->close   = RT_NULL;
     device->read    = i2c_bus_device_read;
diff --git a/components/drivers/spi/spi_dev.c b/components/drivers/spi/spi_dev.c
index b1f6e41a861f18422313f4b004d4b66351202a30..375a5e0fa100d18506277cff8894723ad2720283 100644
--- a/components/drivers/spi/spi_dev.c
+++ b/components/drivers/spi/spi_dev.c
@@ -25,16 +25,6 @@
 #include <drivers/spi.h>
 
 /* SPI bus device interface, compatible with RT-Thread 0.3.x/1.0.x */
-static rt_err_t _spi_bus_device_init(rt_device_t dev)
-{
-    struct rt_spi_bus *bus;
-
-    bus = (struct rt_spi_bus *)dev;
-    RT_ASSERT(bus != RT_NULL);
-
-    return RT_EOK;
-}
-
 static rt_size_t _spi_bus_device_read(rt_device_t dev,
                                       rt_off_t    pos,
                                       void       *buffer,
@@ -67,11 +57,7 @@ static rt_err_t _spi_bus_device_control(rt_device_t dev,
                                         rt_uint8_t  cmd,
                                         void       *args)
 {
-    struct rt_spi_bus *bus;
-
-    bus = (struct rt_spi_bus *)dev;
-    RT_ASSERT(bus != RT_NULL);
-
+    /* TODO: add control command handle */
     switch (cmd)
     {
     case 0: /* set device */
@@ -93,7 +79,7 @@ rt_err_t rt_spi_bus_device_init(struct rt_spi_bus *bus, const char *name)
     /* set device type */
     device->type    = RT_Device_Class_SPIBUS;
     /* initialize device interface */
-    device->init    = _spi_bus_device_init;
+    device->init    = RT_NULL;
     device->open    = RT_NULL;
     device->close   = RT_NULL;
     device->read    = _spi_bus_device_read;
@@ -105,16 +91,6 @@ rt_err_t rt_spi_bus_device_init(struct rt_spi_bus *bus, const char *name)
 }
 
 /* SPI Dev device interface, compatible with RT-Thread 0.3.x/1.0.x */
-static rt_err_t _spidev_device_init(rt_device_t dev)
-{
-    struct rt_spi_device *device;
-
-    device = (struct rt_spi_device *)dev;
-    RT_ASSERT(device != RT_NULL);
-
-    return RT_EOK;
-}
-
 static rt_size_t _spidev_device_read(rt_device_t dev,
                                      rt_off_t    pos,
                                      void       *buffer,
@@ -147,11 +123,6 @@ static rt_err_t _spidev_device_control(rt_device_t dev,
                                        rt_uint8_t  cmd,
                                        void       *args)
 {
-    struct rt_spi_device *device;
-
-    device = (struct rt_spi_device *)dev;
-    RT_ASSERT(device != RT_NULL);
-
     switch (cmd)
     {
     case 0: /* set device */
@@ -172,7 +143,7 @@ rt_err_t rt_spidev_device_init(struct rt_spi_device *dev, const char *name)
 
     /* set device type */
     device->type    = RT_Device_Class_SPIDevice;
-    device->init    = _spidev_device_init;
+    device->init    = RT_NULL;
     device->open    = RT_NULL;
     device->close   = RT_NULL;
     device->read    = _spidev_device_read;