diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index d477a0d2..a865ba3c 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -229,13 +229,13 @@ void cdcd_reset(uint8_t rhport)
   }
 }
 
-tusb_error_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * p_interface_desc, uint16_t *p_length)
+tusb_error_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_length)
 {
-  if ( CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL != p_interface_desc->bInterfaceSubClass) return TUSB_ERROR_CDC_UNSUPPORTED_SUBCLASS;
+  if ( CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL != itf_desc->bInterfaceSubClass) return TUSB_ERROR_CDC_UNSUPPORTED_SUBCLASS;
 
   // Only support AT commands, no protocol and vendor specific commands.
-  if ( !(tu_within(CDC_COMM_PROTOCOL_NONE, p_interface_desc->bInterfaceProtocol, CDC_COMM_PROTOCOL_ATCOMMAND_CDMA) ||
-         p_interface_desc->bInterfaceProtocol == 0xff ) )
+  if ( !(tu_within(CDC_COMM_PROTOCOL_NONE, itf_desc->bInterfaceProtocol, CDC_COMM_PROTOCOL_ATCOMMAND_CDMA) ||
+         itf_desc->bInterfaceProtocol == 0xff ) )
   {
     return TUSB_ERROR_CDC_UNSUPPORTED_PROTOCOL;
   }
@@ -252,16 +252,16 @@ tusb_error_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * p_interface
   }
 
   //------------- Control Interface -------------//
-  p_cdc->itf_num  = p_interface_desc->bInterfaceNumber;
+  p_cdc->itf_num  = itf_desc->bInterfaceNumber;
 
-  uint8_t const * p_desc = descriptor_next ( (uint8_t const *) p_interface_desc );
+  uint8_t const * p_desc = tu_desc_next( itf_desc );
   (*p_length) = sizeof(tusb_desc_interface_t);
 
   // Communication Functional Descriptors
   while( TUSB_DESC_CLASS_SPECIFIC == p_desc[DESC_OFFSET_TYPE] )
   {
     (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
   if ( TUSB_DESC_ENDPOINT == p_desc[DESC_OFFSET_TYPE])
@@ -271,7 +271,7 @@ tusb_error_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * p_interface
     p_cdc->ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
 
     (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
   //------------- Data Interface (if any) -------------//
@@ -280,7 +280,7 @@ tusb_error_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * p_interface
   {
     // next to endpoint descritpor
     (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
 
     // Open endpoint pair with usbd helper
     tusb_desc_endpoint_t const *p_desc_ep = (tusb_desc_endpoint_t const *) p_desc;
diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index d660cc39..d6767d0a 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -146,7 +146,7 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
   uint8_t const * p_desc;
   cdch_data_t * p_cdc;
 
-  p_desc = descriptor_next ( (uint8_t const *) itf_desc );
+  p_desc = tu_desc_next(itf_desc);
   p_cdc  = &cdch_data[dev_addr-1];
 
   p_cdc->itf_num   = itf_desc->bInterfaceNumber;
@@ -165,7 +165,7 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
     }
 
     (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
   if ( TUSB_DESC_ENDPOINT == p_desc[DESC_OFFSET_TYPE])
@@ -177,7 +177,7 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
     p_cdc->ep_notif = ep_desc->bEndpointAddress;
 
     (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
   //------------- Data Interface (if any) -------------//
@@ -185,7 +185,7 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
        (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )
   {
     (*p_length) += p_desc[DESC_OFFSET_LEN];
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
 
     // data endpoints expected to be in pairs
     for(uint32_t i=0; i<2; i++)
@@ -205,7 +205,7 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
       }
 
       (*p_length) += p_desc[DESC_OFFSET_LEN];
-      p_desc = descriptor_next( p_desc );
+      p_desc = tu_desc_next( p_desc );
     }
   }
 
diff --git a/src/class/custom/custom_device.c b/src/class/custom/custom_device.c
index 5abffacf..bec6f42d 100644
--- a/src/class/custom/custom_device.c
+++ b/src/class/custom/custom_device.c
@@ -76,7 +76,7 @@ tusb_error_t cusd_open(uint8_t rhport, tusb_desc_interface_t const * p_desc_itf,
   cusd_interface_t* p_itf = &_cusd_itf;
 
   // Open endpoint pair with usbd helper
-  tusb_desc_endpoint_t const *p_desc_ep = (tusb_desc_endpoint_t const *) descriptor_next( (uint8_t const*) p_desc_itf );
+  tusb_desc_endpoint_t const *p_desc_ep = (tusb_desc_endpoint_t const *) tu_desc_next( (uint8_t const*) p_desc_itf );
   TU_ASSERT_ERR( usbd_open_edpt_pair(rhport, p_desc_ep, TUSB_XFER_BULK, &p_itf->ep_out, &p_itf->ep_in) );
 
   p_itf->itf_num = p_desc_itf->bInterfaceNumber;
diff --git a/src/class/custom/custom_host.c b/src/class/custom/custom_host.c
index e840a282..894e641e 100644
--- a/src/class/custom/custom_host.c
+++ b/src/class/custom/custom_host.c
@@ -111,7 +111,7 @@ tusb_error_t cush_open_subtask(uint8_t dev_addr, tusb_desc_interface_t const *p_
 {
   // FIXME quick hack to test lpc1k custom class with 2 bulk endpoints
   uint8_t const *p_desc = (uint8_t const *) p_interface_desc;
-  p_desc = descriptor_next(p_desc);
+  p_desc = tu_desc_next(p_desc);
 
   //------------- Bulk Endpoints Descriptor -------------//
   for(uint32_t i=0; i<2; i++)
@@ -124,7 +124,7 @@ tusb_error_t cush_open_subtask(uint8_t dev_addr, tusb_desc_interface_t const *p_
     *p_pipe_hdl = hcd_edpt_open(dev_addr, p_endpoint, TUSB_CLASS_VENDOR_SPECIFIC);
     TU_ASSERT ( pipehandle_is_valid(*p_pipe_hdl), TUSB_ERROR_HCD_OPEN_PIPE_FAILED );
 
-    p_desc = descriptor_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
   (*p_length) = sizeof(tusb_desc_interface_t) + 2*sizeof(tusb_desc_endpoint_t);
diff --git a/src/class/msc/msc_device.c b/src/class/msc/msc_device.c
index 83c9990d..48f23688 100644
--- a/src/class/msc/msc_device.c
+++ b/src/class/msc/msc_device.c
@@ -150,19 +150,19 @@ void mscd_reset(uint8_t rhport)
   tu_memclr(&_mscd_itf, sizeof(mscd_interface_t));
 }
 
-tusb_error_t mscd_open(uint8_t rhport, tusb_desc_interface_t const * p_desc_itf, uint16_t *p_len)
+tusb_error_t mscd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t *p_len)
 {
   // only support SCSI's BOT protocol
-  TU_VERIFY( ( MSC_SUBCLASS_SCSI == p_desc_itf->bInterfaceSubClass &&
-            MSC_PROTOCOL_BOT  == p_desc_itf->bInterfaceProtocol ), TUSB_ERROR_MSC_UNSUPPORTED_PROTOCOL );
+  TU_VERIFY( ( MSC_SUBCLASS_SCSI == itf_desc->bInterfaceSubClass &&
+            MSC_PROTOCOL_BOT  == itf_desc->bInterfaceProtocol ), TUSB_ERROR_MSC_UNSUPPORTED_PROTOCOL );
 
   mscd_interface_t * p_msc = &_mscd_itf;
 
   // Open endpoint pair with usbd helper
-  tusb_desc_endpoint_t const *p_desc_ep = (tusb_desc_endpoint_t const *) descriptor_next( (uint8_t const*) p_desc_itf );
+  tusb_desc_endpoint_t const *p_desc_ep = (tusb_desc_endpoint_t const *) tu_desc_next( itf_desc );
   TU_ASSERT_ERR( usbd_open_edpt_pair(rhport, p_desc_ep, TUSB_XFER_BULK, &p_msc->ep_out, &p_msc->ep_in) );
 
-  p_msc->itf_num = p_desc_itf->bInterfaceNumber;
+  p_msc->itf_num = itf_desc->bInterfaceNumber;
   (*p_len) = sizeof(tusb_desc_interface_t) + 2*sizeof(tusb_desc_endpoint_t);
 
   //------------- Queue Endpoint OUT for Command Block Wrapper -------------//
diff --git a/src/class/msc/msc_host.c b/src/class/msc/msc_host.c
index dd771440..86669b27 100644
--- a/src/class/msc/msc_host.c
+++ b/src/class/msc/msc_host.c
@@ -300,7 +300,7 @@ bool msch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
   msch_interface_t* p_msc = &msch_data[dev_addr-1];
 
   //------------- Open Data Pipe -------------//
-  tusb_desc_endpoint_t const * ep_desc = (tusb_desc_endpoint_t const *) descriptor_next( (uint8_t const*) itf_desc );
+  tusb_desc_endpoint_t const * ep_desc = (tusb_desc_endpoint_t const *) tu_desc_next(itf_desc);
 
   for(uint32_t i=0; i<2; i++)
   {
@@ -317,7 +317,7 @@ bool msch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
       p_msc->ep_out = ep_desc->bEndpointAddress;
     }
 
-    ep_desc = (tusb_desc_endpoint_t const *) descriptor_next( (uint8_t const*)  ep_desc );
+    ep_desc = (tusb_desc_endpoint_t const *) tu_desc_next(ep_desc);
   }
 
   p_msc->itf_numr = itf_desc->bInterfaceNumber;
diff --git a/src/common/tusb_types.h b/src/common/tusb_types.h
index cbddd415..cf02952a 100644
--- a/src/common/tusb_types.h
+++ b/src/common/tusb_types.h
@@ -395,19 +395,20 @@ static inline uint8_t tu_edpt_addr(uint8_t num, uint8_t dir)
 //--------------------------------------------------------------------+
 // Descriptor helper
 //--------------------------------------------------------------------+
-static inline uint8_t const * descriptor_next(uint8_t const p_desc[])
+static inline uint8_t const * tu_desc_next(void const* desc)
 {
-  return p_desc + p_desc[DESC_OFFSET_LEN];
+  uint8_t const* desc8 = (uint8_t const*) desc;
+  return desc8 + desc8[DESC_OFFSET_LEN];
 }
 
-static inline uint8_t descriptor_type(uint8_t const p_desc[])
+static inline uint8_t tu_desc_type(void const* desc)
 {
-  return p_desc[DESC_OFFSET_TYPE];
+  return ((uint8_t const*) desc)[DESC_OFFSET_TYPE];
 }
 
-static inline uint8_t descriptor_len(uint8_t const p_desc[])
+static inline uint8_t tu_desc_len(void const* desc)
 {
-  return p_desc[DESC_OFFSET_LEN];
+  return ((uint8_t const*) desc)[DESC_OFFSET_LEN];
 }
 
 // Length of the string descriptors in bytes with slen characters
diff --git a/src/device/usbd.c b/src/device/usbd.c
index b63dcb13..09643774 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -436,12 +436,12 @@ static bool process_set_config(uint8_t rhport)
   while( p_desc < desc_cfg + cfg_len )
   {
     // Each interface always starts with Interface or Association descriptor
-    if ( TUSB_DESC_INTERFACE_ASSOCIATION == descriptor_type(p_desc) )
+    if ( TUSB_DESC_INTERFACE_ASSOCIATION == tu_desc_type(p_desc) )
     {
-      p_desc = descriptor_next(p_desc); // ignore Interface Association
+      p_desc = tu_desc_next(p_desc); // ignore Interface Association
     }else
     {
-      TU_ASSERT( TUSB_DESC_INTERFACE == descriptor_type(p_desc) );
+      TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
 
       tusb_desc_interface_t* desc_itf = (tusb_desc_interface_t*) p_desc;
 
@@ -480,15 +480,15 @@ static void mark_interface_endpoint(uint8_t ep2drv[8][2], uint8_t const* p_desc,
 
   while( len < desc_len )
   {
-    if ( TUSB_DESC_ENDPOINT == descriptor_type(p_desc) )
+    if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
     {
       uint8_t const ep_addr = ((tusb_desc_endpoint_t const*) p_desc)->bEndpointAddress;
 
       ep2drv[tu_edpt_number(ep_addr)][tu_edpt_dir(ep_addr)] = driver_id;
     }
 
-    len   += descriptor_len(p_desc);
-    p_desc = descriptor_next(p_desc);
+    len   += tu_desc_len(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 }
 
@@ -641,7 +641,7 @@ tusb_error_t usbd_open_edpt_pair(uint8_t rhport, tusb_desc_endpoint_t const* ep_
       (*ep_out) = ep_desc->bEndpointAddress;
     }
 
-    ep_desc = (tusb_desc_endpoint_t const *) descriptor_next( (uint8_t const*)  ep_desc );
+    ep_desc = (tusb_desc_endpoint_t const *) tu_desc_next(ep_desc);
   }
 
   return TUSB_ERROR_NONE;
diff --git a/src/host/hub.c b/src/host/hub.c
index e2e91d73..e9f9dc7d 100644
--- a/src/host/hub.c
+++ b/src/host/hub.c
@@ -156,21 +156,21 @@ void hub_init(void)
 //  hub_enum_sem_hdl = osal_semaphore_create( OSAL_SEM_REF(hub_enum_semaphore) );
 }
 
-bool hub_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *p_interface_desc, uint16_t *p_length)
+bool hub_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *itf_desc, uint16_t *p_length)
 {
   // not support multiple TT yet
-  if ( p_interface_desc->bInterfaceProtocol > 1 ) return false;
+  if ( itf_desc->bInterfaceProtocol > 1 ) return false;
 
   //------------- Open Interrupt Status Pipe -------------//
   tusb_desc_endpoint_t const *ep_desc;
-  ep_desc = (tusb_desc_endpoint_t const *) descriptor_next( (uint8_t const*) p_interface_desc );
+  ep_desc = (tusb_desc_endpoint_t const *) tu_desc_next(itf_desc);
 
   TU_ASSERT(TUSB_DESC_ENDPOINT == ep_desc->bDescriptorType);
   TU_ASSERT(TUSB_XFER_INTERRUPT == ep_desc->bmAttributes.xfer);
   
   TU_ASSERT(hcd_edpt_open(rhport, dev_addr, ep_desc));
 
-  hub_data[dev_addr-1].itf_num = p_interface_desc->bInterfaceNumber;
+  hub_data[dev_addr-1].itf_num = itf_desc->bInterfaceNumber;
   hub_data[dev_addr-1].ep_status = ep_desc->bEndpointAddress;
 
   (*p_length) = sizeof(tusb_desc_interface_t) + sizeof(tusb_desc_endpoint_t);
diff --git a/src/host/usbh.c b/src/host/usbh.c
index 369ddd2a..bbe60362 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -560,9 +560,9 @@ bool enum_task(hcd_event_t* event)
   while( p_desc < _usbh_ctrl_buf + ((tusb_desc_configuration_t*)_usbh_ctrl_buf)->wTotalLength )
   {
     // skip until we see interface descriptor
-    if ( TUSB_DESC_INTERFACE != descriptor_type(p_desc) )
+    if ( TUSB_DESC_INTERFACE != tu_desc_type(p_desc) )
     {
-      p_desc = descriptor_next(p_desc); // skip the descriptor, increase by the descriptor's length
+      p_desc = tu_desc_next(p_desc); // skip the descriptor, increase by the descriptor's length
     }else
     {
       tusb_desc_interface_t* desc_itf = (tusb_desc_interface_t*) p_desc;
@@ -577,7 +577,7 @@ bool enum_task(hcd_event_t* event)
       if( drv_id >= USBH_CLASS_DRIVER_COUNT )
       {
         // skip unsupported class
-        p_desc = descriptor_next(p_desc);
+        p_desc = tu_desc_next(p_desc);
       }
       else
       {
@@ -589,7 +589,7 @@ bool enum_task(hcd_event_t* event)
         {
           // TODO Attach hub to Hub is not currently supported
           // skip this interface
-          p_desc = descriptor_next(p_desc);
+          p_desc = tu_desc_next(p_desc);
         }
         else
         {
@@ -685,15 +685,15 @@ static void mark_interface_endpoint(uint8_t ep2drv[8][2], uint8_t const* p_desc,
 
   while( len < desc_len )
   {
-    if ( TUSB_DESC_ENDPOINT == descriptor_type(p_desc) )
+    if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
     {
       uint8_t const ep_addr = ((tusb_desc_endpoint_t const*) p_desc)->bEndpointAddress;
 
       ep2drv[ tu_edpt_number(ep_addr) ][ tu_edpt_dir(ep_addr) ] = driver_id;
     }
 
-    len   += descriptor_len(p_desc);
-    p_desc = descriptor_next(p_desc);
+    len   += tu_desc_len(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 }