diff --git a/media/mtp/MtpDataPacket.h b/media/mtp/MtpDataPacket.h
index 6240f28..82e0ee4 100644
--- a/media/mtp/MtpDataPacket.h
+++ b/media/mtp/MtpDataPacket.h
@@ -93,7 +93,6 @@
     inline void         putEmptyString() { putUInt8(0); }
     inline void         putEmptyArray() { putUInt32(0); }
 
-
 #ifdef MTP_DEVICE
     // fill our buffer with data from the given file descriptor
     int                 read(int fd);
@@ -110,9 +109,15 @@
     int                 readDataWait(struct usb_device *device);
     int                 readDataHeader(struct usb_request *ep);
 
-    int                 writeDataHeader(struct usb_request *ep, uint32_t length);
-    int                 write(struct usb_request *ep);
-    int                 write(struct usb_request *ep, void* buffer, uint32_t length);
+    // Write a whole data packet with payload to the end point given by a request. |divisionMode|
+    // specifies whether to divide header and payload. See |UrbPacketDivisionMode| for meanings of
+    // each value. Return the number of bytes (including header size) sent to the device on success.
+    // Otherwise -1.
+    int                 write(struct usb_request *request, UrbPacketDivisionMode divisionMode);
+    // Similar to previous write method but it reads the payload from |fd|. If |size| is larger than
+    // MTP_BUFFER_SIZE, the data will be sent by multiple bulk transfer requests.
+    int                 write(struct usb_request *request, UrbPacketDivisionMode divisionMode,
+                              int fd, size_t size);
 #endif
 
     inline bool         hasData() const { return mPacketSize > MTP_CONTAINER_HEADER_SIZE; }