USB: Interface Association Descriptors added to CDC & RNDIS

Without Interface Association Descriptor, the CDC serial and
RNDIS functions did not work correctly when added to a
composite gadget with other functions.  This is because, it
defined two interfaces and some hosts tried to treat each
interface separatelly.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 31 insertions, 4 deletions

diff --git a/drivers/usb/gadget/f_rndis.c b/drivers/usb/gadget/f_rndis.c
index c9966cc..95dae4c 100644
--- a/drivers/usb/gadget/f_rndis.c
+++ b/drivers/usb/gadget/f_rndis.c
@@ -4,6 +4,8 @@
  * Copyright (C) 2003-2005,2008 David Brownell
  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
  * Copyright (C) 2008 Nokia Corporation
+ * Copyright (C) 2009 Samsung Electronics
+ *                    Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -149,8 +151,8 @@ static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor __initdata = {
 	.bDataInterface =	0x01,
 };
 
-static struct usb_cdc_acm_descriptor acm_descriptor __initdata = {
-	.bLength =		sizeof acm_descriptor,
+static struct usb_cdc_acm_descriptor rndis_acm_descriptor __initdata = {
+	.bLength =		sizeof rndis_acm_descriptor,
 	.bDescriptorType =	USB_DT_CS_INTERFACE,
 	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
 
@@ -179,6 +181,20 @@ static struct usb_interface_descriptor rndis_data_intf __initdata = {
 	/* .iInterface = DYNAMIC */
 };
 
+
+static struct usb_interface_assoc_descriptor
+rndis_iad_descriptor = {
+	.bLength =		sizeof rndis_iad_descriptor,
+	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
+
+	.bFirstInterface =	0, /* XXX, hardcoded */
+	.bInterfaceCount = 	2,	// control + data
+	.bFunctionClass =	USB_CLASS_COMM,
+	.bFunctionSubClass =	USB_CDC_SUBCLASS_ETHERNET,
+	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
+	/* .iFunction = DYNAMIC */
+};
+
 /* full speed support: */
 
 static struct usb_endpoint_descriptor fs_notify_desc __initdata = {
@@ -208,11 +224,12 @@ static struct usb_endpoint_descriptor fs_out_desc __initdata = {
 };
 
 static struct usb_descriptor_header *eth_fs_function[] __initdata = {
+	(struct usb_descriptor_header *) &rndis_iad_descriptor,
 	/* control interface matches ACM, not Ethernet */
 	(struct usb_descriptor_header *) &rndis_control_intf,
 	(struct usb_descriptor_header *) &header_desc,
 	(struct usb_descriptor_header *) &call_mgmt_descriptor,
-	(struct usb_descriptor_header *) &acm_descriptor,
+	(struct usb_descriptor_header *) &rndis_acm_descriptor,
 	(struct usb_descriptor_header *) &rndis_union_desc,
 	(struct usb_descriptor_header *) &fs_notify_desc,
 	/* data interface has no altsetting */
@@ -252,11 +269,12 @@ static struct usb_endpoint_descriptor hs_out_desc __initdata = {
 };
 
 static struct usb_descriptor_header *eth_hs_function[] __initdata = {
+	(struct usb_descriptor_header *) &rndis_iad_descriptor,
 	/* control interface matches ACM, not Ethernet */
 	(struct usb_descriptor_header *) &rndis_control_intf,
 	(struct usb_descriptor_header *) &header_desc,
 	(struct usb_descriptor_header *) &call_mgmt_descriptor,
-	(struct usb_descriptor_header *) &acm_descriptor,
+	(struct usb_descriptor_header *) &rndis_acm_descriptor,
 	(struct usb_descriptor_header *) &rndis_union_desc,
 	(struct usb_descriptor_header *) &hs_notify_desc,
 	/* data interface has no altsetting */
@@ -271,6 +289,7 @@ static struct usb_descriptor_header *eth_hs_function[] __initdata = {
 static struct usb_string rndis_string_defs[] = {
 	[0].s = "RNDIS Communications Control",
 	[1].s = "RNDIS Ethernet Data",
+	[2].s = "RNDIS",
 	{  } /* end of list */
 };
 
@@ -587,6 +606,7 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
 	if (status < 0)
 		goto fail;
 	rndis->ctrl_id = status;
+	rndis_iad_descriptor.bFirstInterface = status;
 
 	rndis_control_intf.bInterfaceNumber = status;
 	rndis_union_desc.bMasterInterface0 = status;
@@ -798,6 +818,13 @@ int __init rndis_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
 			return status;
 		rndis_string_defs[1].id = status;
 		rndis_data_intf.iInterface = status;
+
+		/* IAD iFunction label */
+		status = usb_string_id(c->cdev);
+		if (status < 0)
+			return status;
+		rndis_string_defs[2].id = status;
+		rndis_iad_descriptor.iFunction = status;
 	}
 
 	/* allocate and initialize one new instance */