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, 28 insertions, 0 deletions

diff --git a/drivers/usb/gadget/f_acm.c b/drivers/usb/gadget/f_acm.c
index 4e3657808b0f..d10353d46b86 100644
--- a/drivers/usb/gadget/f_acm.c
+++ b/drivers/usb/gadget/f_acm.c
@@ -4,6 +4,8 @@
  * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
  * Copyright (C) 2008 by David Brownell
  * Copyright (C) 2008 by Nokia Corporation
+ * Copyright (C) 2009 by Samsung Electronics
+ * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
  *
  * This software is distributed under the terms of the GNU General
  * Public License ("GPL") as published by the Free Software Foundation,
@@ -99,6 +101,20 @@ static inline struct f_acm *port_to_acm(struct gserial *p)
 
 /* interface and class descriptors: */
 
+static struct usb_interface_assoc_descriptor
+acm_iad_descriptor = {
+        .bLength =              sizeof acm_iad_descriptor,
+        .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
+
+        /* .bFirstInterface =   DYNAMIC, */
+        .bInterfaceCount =      2,      // control + data
+        .bFunctionClass =       USB_CLASS_COMM,
+        .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
+        .bFunctionProtocol =    USB_CDC_PROTO_NONE,
+        /* .iFunction =         DYNAMIC */
+};
+
+
 static struct usb_interface_descriptor acm_control_interface_desc __initdata = {
         .bLength =              USB_DT_INTERFACE_SIZE,
         .bDescriptorType =      USB_DT_INTERFACE,
@@ -178,6 +194,7 @@ static struct usb_endpoint_descriptor acm_fs_out_desc __initdata = {
 };
 
 static struct usb_descriptor_header *acm_fs_function[] __initdata = {
+        (struct usb_descriptor_header *) &acm_iad_descriptor,
         (struct usb_descriptor_header *) &acm_control_interface_desc,
         (struct usb_descriptor_header *) &acm_header_desc,
         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
@@ -216,6 +233,7 @@ static struct usb_endpoint_descriptor acm_hs_out_desc __initdata = {
 };
 
 static struct usb_descriptor_header *acm_hs_function[] __initdata = {
+        (struct usb_descriptor_header *) &acm_iad_descriptor,
         (struct usb_descriptor_header *) &acm_control_interface_desc,
         (struct usb_descriptor_header *) &acm_header_desc,
         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
@@ -232,11 +250,13 @@ static struct usb_descriptor_header *acm_hs_function[] __initdata = {
 
 #define ACM_CTRL_IDX    0
 #define ACM_DATA_IDX    1
+#define ACM_IAD_IDX     2
 
 /* static strings, in UTF-8 */
 static struct usb_string acm_string_defs[] = {
         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
         [ACM_DATA_IDX].s = "CDC ACM Data",
+        [ACM_IAD_IDX ].s = "CDC Serial",
         {  /* ZEROES END LIST */ },
 };
 
@@ -563,6 +583,7 @@ acm_bind(struct usb_configuration *c, struct usb_function *f)
         if (status < 0)
                 goto fail;
         acm->ctrl_id = status;
+        acm_iad_descriptor.bFirstInterface = status;
 
         acm_control_interface_desc.bInterfaceNumber = status;
         acm_union_desc .bMasterInterface0 = status;
@@ -732,6 +753,13 @@ int __init acm_bind_config(struct usb_configuration *c, u8 port_num)
                 acm_string_defs[ACM_DATA_IDX].id = status;
 
                 acm_data_interface_desc.iInterface = status;
+
+                status = usb_string_id(c->cdev);
+                if (status < 0)
+                        return status;
+                acm_string_defs[ACM_IAD_IDX].id = status;
+
+                acm_iad_descriptor.iFunction = status;
         }
 
         /* allocate and initialize one new instance */