USB: audio gadget: fix wTotalLength calculation

The wTotalLength should contain the sum of the interface and unit
descriptor sizes per the Audio Device Class specification 1.0.
Reported-by: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/f_audio.c

@@ -56,13 +56,16 @@ static struct usb_interface_descriptor ac_interface_desc __initdata = {
 DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
 
 #define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
+/* 1 input terminal, 1 output terminal and 1 feature unit */
+#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
+	+ UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
 /* B.3.2  Class-Specific AC Interface Descriptor */
 static struct uac_ac_header_descriptor_2 ac_header_desc = {
 	.bLength =		UAC_DT_AC_HEADER_LENGTH,
 	.bDescriptorType =	USB_DT_CS_INTERFACE,
 	.bDescriptorSubtype =	UAC_HEADER,
 	.bcdADC =		__constant_cpu_to_le16(0x0100),
-	.wTotalLength =		__constant_cpu_to_le16(UAC_DT_AC_HEADER_LENGTH),
+	.wTotalLength =		__constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
 	.bInCollection =	F_AUDIO_NUM_INTERFACES,
 	.baInterfaceNr = {
 		[0] =		F_AUDIO_AC_INTERFACE,