3 files changed, 24 insertions, 4 deletions

diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h
index 2a4b4a72a4f9..ecb3a31f7ca6 100644
--- a/include/uapi/linux/usb/functionfs.h
+++ b/include/uapi/linux/usb/functionfs.h
@@ -53,7 +53,7 @@ struct usb_endpoint_descriptor_no_audio {
  * structure.  Any flags that are not recognised cause the whole block to be
  * rejected with -ENOSYS.
  *
- * Legacy descriptors format:
+ * Legacy descriptors format (deprecated as of 3.14):
  *
  * | off | name      | type         | description                          |
  * |-----+-----------+--------------+--------------------------------------|
diff --git a/tools/usb/Makefile b/tools/usb/Makefile
index acf2165c04e6..d576b3bac3cf 100644
--- a/tools/usb/Makefile
+++ b/tools/usb/Makefile
@@ -6,7 +6,11 @@ WARNINGS = -Wall -Wextra
 CFLAGS = $(WARNINGS) -g -I../include
 LDFLAGS = $(PTHREAD_LIBS)
 
-all: testusb ffs-test
+all: testusb ffs-test ffs-test-legacy
+
+ffs-test-legacy: ffs-test.c
+        $(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) -DUSE_LEGACY_DESC_HEAD
+
 %: %.c
         $(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
 
diff --git a/tools/usb/ffs-test.c b/tools/usb/ffs-test.c
index fe1e66b6ef40..74b353d9eb50 100644
--- a/tools/usb/ffs-test.c
+++ b/tools/usb/ffs-test.c
@@ -1,5 +1,5 @@
 /*
- * ffs-test.c.c -- user mode filesystem api for usb composite function
+ * ffs-test.c -- user mode filesystem api for usb composite function
  *
  * Copyright (C) 2010 Samsung Electronics
  *                    Author: Michal Nazarewicz <mina86@mina86.com>
@@ -21,6 +21,8 @@
 
 /* $(CROSS_COMPILE)cc -Wall -Wextra -g -o ffs-test ffs-test.c -lpthread */
 
+/* Uncomment to make the tool use legacy FFS descriptor headers. */
+/* #define USE_LEGACY_DESC_HEAD */
 
 #define _BSD_SOURCE /* for endian.h */
 
@@ -106,7 +108,15 @@ static void _msg(unsigned level, const char *fmt, ...)
 /******************** Descriptors and Strings *******************************/
 
 static const struct {
-        struct usb_functionfs_descs_head header;
+        struct {
+                __le32 magic;
+                __le32 length;
+#ifndef USE_LEGACY_DESC_HEAD
+                __le32 flags;
+#endif
+                __le32 fs_count;
+                __le32 hs_count;
+        } __attribute__((packed)) header;
         struct {
                 struct usb_interface_descriptor intf;
                 struct usb_endpoint_descriptor_no_audio sink;
@@ -114,7 +124,13 @@ static const struct {
         } __attribute__((packed)) fs_descs, hs_descs;
 } __attribute__((packed)) descriptors = {
         .header = {
+#ifdef USE_LEGACY_DESC_HEAD
                 .magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC),
+#else
+                .magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
+                .flags = cpu_to_le32(FUNCTIONFS_HAS_FS_DESC |
+                                     FUNCTIONFS_HAS_HS_DESC),
+#endif
                 .length = cpu_to_le32(sizeof descriptors),
                 .fs_count = 3,
                 .hs_count = 3,