Merge tag 'usb-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb into next

Pull USB driver updates from Greg KH:
 "Here is the big USB driver pull request for 3.16-rc1.

  Nothing huge here, but lots of little things in the USB core, and in
  lots of drivers.  Hopefully the USB power management will be work
  better now that it has been reworked to do per-port power control
  dynamically.  There's also a raft of gadget driver updates and fixes,
  CONFIG_USB_DEBUG is finally gone now that everything has been
  converted over to the dynamic debug inteface, the last hold-out
  drivers were cleaned up and the config option removed.  There were
  also other minor things all through the drivers/usb/ tree, the
  shortlog shows this pretty well.

  All have been in linux-next, including the very last patch, which came
  from linux-next to fix a build issue on some platforms"

* tag 'usb-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (314 commits)
  usb: hub_handle_remote_wakeup() only exists for CONFIG_PM=y
  USB: orinoco_usb: remove CONFIG_USB_DEBUG support
  USB: media: lirc: igorplugusb: remove CONFIG_USB_DEBUG support
  USB: media: streamzap: remove CONFIG_USB_DEBUG
  USB: media: redrat3: remove CONFIG_USB_DEBUG usage
  USB: media: redrat3: remove unneeded tracing macro
  usb: qcserial: add additional Sierra Wireless QMI devices
  usb: host: max3421-hcd: Use module_spi_driver
  usb: host: max3421-hcd: Allow platform-data to specify Vbus polarity
  usb: host: max3421-hcd: fix "spi_rd8" uses dynamic stack allocation warning
  usb: host: max3421-hcd: Fix missing unlock in max3421_urb_enqueue()
  usb: qcserial: add Netgear AirCard 341U
  Documentation: dt-bindings: update xhci-platform DT binding for R-Car H2 and M2
  usb: host: xhci-plat: add xhci_plat_start()
  usb: host: max3421-hcd: Fix potential NULL urb dereference
  Revert "usb: gadget: net2280: Add support for PLX USB338X"
  USB: usbip: remove CONFIG_USB_DEBUG reference
  USB: remove CONFIG_USB_DEBUG from defconfig files
  usb: resume child device when port is powered on
  usb: hub_handle_remote_wakeup() depends on CONFIG_PM_RUNTIME=y
  ...

1 files changed, 552 insertions, 4 deletions

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 7d1cc01796b..2ddcd635ca2 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -2,9 +2,12 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <linux/nls.h>
 #include <linux/usb/composite.h>
 #include <linux/usb/gadget_configfs.h>
 #include "configfs.h"
+#include "u_f.h"
+#include "u_os_desc.h"
 
 int check_user_usb_string(const char *name,
 		struct usb_gadget_strings *stringtab_dev)
@@ -43,7 +46,8 @@ struct gadget_info {
 	struct config_group functions_group;
 	struct config_group configs_group;
 	struct config_group strings_group;
-	struct config_group *default_groups[4];
+	struct config_group os_desc_group;
+	struct config_group *default_groups[5];
 
 	struct mutex lock;
 	struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
@@ -56,6 +60,9 @@ struct gadget_info {
 #endif
 	struct usb_composite_driver composite;
 	struct usb_composite_dev cdev;
+	bool use_os_desc;
+	char b_vendor_code;
+	char qw_sign[OS_STRING_QW_SIGN_LEN];
 };
 
 struct config_usb_cfg {
@@ -79,6 +86,10 @@ struct gadget_strings {
 	struct list_head list;
 };
 
+struct os_desc {
+	struct config_group group;
+};
+
 struct gadget_config_name {
 	struct usb_gadget_strings stringtab_dev;
 	struct usb_string strings;
@@ -736,6 +747,525 @@ static void gadget_strings_attr_release(struct config_item *item)
 USB_CONFIG_STRING_RW_OPS(gadget_strings);
 USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info);
 
+static inline struct os_desc *to_os_desc(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct os_desc, group);
+}
+
+CONFIGFS_ATTR_STRUCT(os_desc);
+CONFIGFS_ATTR_OPS(os_desc);
+
+static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)
+{
+	struct gadget_info *gi;
+
+	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+
+	return sprintf(page, "%d", gi->use_os_desc);
+}
+
+static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
+				 size_t len)
+{
+	struct gadget_info *gi;
+	int ret;
+	bool use;
+
+	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+
+	mutex_lock(&gi->lock);
+	ret = strtobool(page, &use);
+	if (!ret) {
+		gi->use_os_desc = use;
+		ret = len;
+	}
+	mutex_unlock(&gi->lock);
+
+	return ret;
+}
+
+static struct os_desc_attribute os_desc_use =
+	__CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,
+			os_desc_use_show,
+			os_desc_use_store);
+
+static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)
+{
+	struct gadget_info *gi;
+
+	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+
+	return sprintf(page, "%d", gi->b_vendor_code);
+}
+
+static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
+					   const char *page, size_t len)
+{
+	struct gadget_info *gi;
+	int ret;
+	u8 b_vendor_code;
+
+	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+
+	mutex_lock(&gi->lock);
+	ret = kstrtou8(page, 0, &b_vendor_code);
+	if (!ret) {
+		gi->b_vendor_code = b_vendor_code;
+		ret = len;
+	}
+	mutex_unlock(&gi->lock);
+
+	return ret;
+}
+
+static struct os_desc_attribute os_desc_b_vendor_code =
+	__CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,
+			os_desc_b_vendor_code_show,
+			os_desc_b_vendor_code_store);
+
+static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)
+{
+	struct gadget_info *gi;
+
+	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+
+	memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
+
+	return OS_STRING_QW_SIGN_LEN;
+}
+
+static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
+				     size_t len)
+{
+	struct gadget_info *gi;
+	int res, l;
+
+	gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+	l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
+	if (page[l - 1] == '\n')
+		--l;
+
+	mutex_lock(&gi->lock);
+	res = utf8s_to_utf16s(page, l,
+			      UTF16_LITTLE_ENDIAN, (wchar_t *) gi->qw_sign,
+			      OS_STRING_QW_SIGN_LEN);
+	if (res > 0)
+		res = len;
+	mutex_unlock(&gi->lock);
+
+	return res;
+}
+
+static struct os_desc_attribute os_desc_qw_sign =
+	__CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,
+			os_desc_qw_sign_show,
+			os_desc_qw_sign_store);
+
+static struct configfs_attribute *os_desc_attrs[] = {
+	&os_desc_use.attr,
+	&os_desc_b_vendor_code.attr,
+	&os_desc_qw_sign.attr,
+	NULL,
+};
+
+static void os_desc_attr_release(struct config_item *item)
+{
+	struct os_desc *os_desc = to_os_desc(item);
+	kfree(os_desc);
+}
+
+static int os_desc_link(struct config_item *os_desc_ci,
+			struct config_item *usb_cfg_ci)
+{
+	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
+					struct gadget_info, os_desc_group);
+	struct usb_composite_dev *cdev = &gi->cdev;
+	struct config_usb_cfg *c_target =
+		container_of(to_config_group(usb_cfg_ci),
+			     struct config_usb_cfg, group);
+	struct usb_configuration *c;
+	int ret;
+
+	mutex_lock(&gi->lock);
+	list_for_each_entry(c, &cdev->configs, list) {
+		if (c == &c_target->c)
+			break;
+	}
+	if (c != &c_target->c) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (cdev->os_desc_config) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	cdev->os_desc_config = &c_target->c;
+	ret = 0;
+
+out:
+	mutex_unlock(&gi->lock);
+	return ret;
+}
+
+static int os_desc_unlink(struct config_item *os_desc_ci,
+			  struct config_item *usb_cfg_ci)
+{
+	struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
+					struct gadget_info, os_desc_group);
+	struct usb_composite_dev *cdev = &gi->cdev;
+
+	mutex_lock(&gi->lock);
+	if (gi->udc_name)
+		unregister_gadget(gi);
+	cdev->os_desc_config = NULL;
+	WARN_ON(gi->udc_name);
+	mutex_unlock(&gi->lock);
+	return 0;
+}
+
+static struct configfs_item_operations os_desc_ops = {
+	.release                = os_desc_attr_release,
+	.show_attribute         = os_desc_attr_show,
+	.store_attribute        = os_desc_attr_store,
+	.allow_link		= os_desc_link,
+	.drop_link		= os_desc_unlink,
+};
+
+static struct config_item_type os_desc_type = {
+	.ct_item_ops	= &os_desc_ops,
+	.ct_attrs	= os_desc_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+CONFIGFS_ATTR_STRUCT(usb_os_desc);
+CONFIGFS_ATTR_OPS(usb_os_desc);
+
+
+static inline struct usb_os_desc_ext_prop
+*to_usb_os_desc_ext_prop(struct config_item *item)
+{
+	return container_of(item, struct usb_os_desc_ext_prop, item);
+}
+
+CONFIGFS_ATTR_STRUCT(usb_os_desc_ext_prop);
+CONFIGFS_ATTR_OPS(usb_os_desc_ext_prop);
+
+static ssize_t ext_prop_type_show(struct usb_os_desc_ext_prop *ext_prop,
+				  char *page)
+{
+	return sprintf(page, "%d", ext_prop->type);
+}
+
+static ssize_t ext_prop_type_store(struct usb_os_desc_ext_prop *ext_prop,
+				   const char *page, size_t len)
+{
+	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
+	u8 type;
+	int ret;
+
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
+	ret = kstrtou8(page, 0, &type);
+	if (ret)
+		goto end;
+	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
+		ret = -EINVAL;
+		goto end;
+	}
+
+	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
+	    ext_prop->type == USB_EXT_PROP_LE32 ||
+	    ext_prop->type == USB_EXT_PROP_BE32) &&
+	    (type == USB_EXT_PROP_UNICODE ||
+	    type == USB_EXT_PROP_UNICODE_ENV ||
+	    type == USB_EXT_PROP_UNICODE_LINK))
+		ext_prop->data_len <<= 1;
+	else if ((ext_prop->type == USB_EXT_PROP_UNICODE ||
+		   ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
+		   ext_prop->type == USB_EXT_PROP_UNICODE_LINK) &&
+		   (type == USB_EXT_PROP_BINARY ||
+		   type == USB_EXT_PROP_LE32 ||
+		   type == USB_EXT_PROP_BE32))
+		ext_prop->data_len >>= 1;
+	ext_prop->type = type;
+	ret = len;
+
+end:
+	if (desc->opts_mutex)
+		mutex_unlock(desc->opts_mutex);
+	return ret;
+}
+
+static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop,
+				  char *page)
+{
+	int len = ext_prop->data_len;
+
+	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
+	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
+	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK)
+		len >>= 1;
+	memcpy(page, ext_prop->data, len);
+
+	return len;
+}
+
+static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop,
+				   const char *page, size_t len)
+{
+	struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
+	char *new_data;
+	size_t ret_len = len;
+
+	if (page[len - 1] == '\n' || page[len - 1] == '\0')
+		--len;
+	new_data = kzalloc(len, GFP_KERNEL);
+	if (!new_data)
+		return -ENOMEM;
+
+	memcpy(new_data, page, len);
+
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
+	kfree(ext_prop->data);
+	ext_prop->data = new_data;
+	desc->ext_prop_len -= ext_prop->data_len;
+	ext_prop->data_len = len;
+	desc->ext_prop_len += ext_prop->data_len;
+	if (ext_prop->type == USB_EXT_PROP_UNICODE ||
+	    ext_prop->type == USB_EXT_PROP_UNICODE_ENV ||
+	    ext_prop->type == USB_EXT_PROP_UNICODE_LINK) {
+		desc->ext_prop_len -= ext_prop->data_len;
+		ext_prop->data_len <<= 1;
+		ext_prop->data_len += 2;
+		desc->ext_prop_len += ext_prop->data_len;
+	}
+	if (desc->opts_mutex)
+		mutex_unlock(desc->opts_mutex);
+	return ret_len;
+}
+
+static struct usb_os_desc_ext_prop_attribute ext_prop_type =
+	__CONFIGFS_ATTR(type, S_IRUGO | S_IWUSR,
+			ext_prop_type_show, ext_prop_type_store);
+
+static struct usb_os_desc_ext_prop_attribute ext_prop_data =
+	__CONFIGFS_ATTR(data, S_IRUGO | S_IWUSR,
+			ext_prop_data_show, ext_prop_data_store);
+
+static struct configfs_attribute *ext_prop_attrs[] = {
+	&ext_prop_type.attr,
+	&ext_prop_data.attr,
+	NULL,
+};
+
+static void usb_os_desc_ext_prop_release(struct config_item *item)
+{
+	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
+
+	kfree(ext_prop); /* frees a whole chunk */
+}
+
+static struct configfs_item_operations ext_prop_ops = {
+	.release		= usb_os_desc_ext_prop_release,
+	.show_attribute		= usb_os_desc_ext_prop_attr_show,
+	.store_attribute	= usb_os_desc_ext_prop_attr_store,
+};
+
+static struct config_item *ext_prop_make(
+		struct config_group *group,
+		const char *name)
+{
+	struct usb_os_desc_ext_prop *ext_prop;
+	struct config_item_type *ext_prop_type;
+	struct usb_os_desc *desc;
+	char *vlabuf;
+
+	vla_group(data_chunk);
+	vla_item(data_chunk, struct usb_os_desc_ext_prop, ext_prop, 1);
+	vla_item(data_chunk, struct config_item_type, ext_prop_type, 1);
+
+	vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
+	if (!vlabuf)
+		return ERR_PTR(-ENOMEM);
+
+	ext_prop = vla_ptr(vlabuf, data_chunk, ext_prop);
+	ext_prop_type = vla_ptr(vlabuf, data_chunk, ext_prop_type);
+
+	desc = container_of(group, struct usb_os_desc, group);
+	ext_prop_type->ct_item_ops = &ext_prop_ops;
+	ext_prop_type->ct_attrs = ext_prop_attrs;
+	ext_prop_type->ct_owner = desc->owner;
+
+	config_item_init_type_name(&ext_prop->item, name, ext_prop_type);
+
+	ext_prop->name = kstrdup(name, GFP_KERNEL);
+	if (!ext_prop->name) {
+		kfree(vlabuf);
+		return ERR_PTR(-ENOMEM);
+	}
+	desc->ext_prop_len += 14;
+	ext_prop->name_len = 2 * strlen(ext_prop->name) + 2;
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
+	desc->ext_prop_len += ext_prop->name_len;
+	list_add_tail(&ext_prop->entry, &desc->ext_prop);
+	++desc->ext_prop_count;
+	if (desc->opts_mutex)
+		mutex_unlock(desc->opts_mutex);
+
+	return &ext_prop->item;
+}
+
+static void ext_prop_drop(struct config_group *group, struct config_item *item)
+{
+	struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
+	struct usb_os_desc *desc = to_usb_os_desc(&group->cg_item);
+
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
+	list_del(&ext_prop->entry);
+	--desc->ext_prop_count;
+	kfree(ext_prop->name);
+	desc->ext_prop_len -= (ext_prop->name_len + ext_prop->data_len + 14);
+	if (desc->opts_mutex)
+		mutex_unlock(desc->opts_mutex);
+	config_item_put(item);
+}
+
+static struct configfs_group_operations interf_grp_ops = {
+	.make_item	= &ext_prop_make,
+	.drop_item	= &ext_prop_drop,
+};
+
+static struct configfs_item_operations interf_item_ops = {
+	.show_attribute		= usb_os_desc_attr_show,
+	.store_attribute	= usb_os_desc_attr_store,
+};
+
+static ssize_t rndis_grp_compatible_id_show(struct usb_os_desc *desc,
+					    char *page)
+{
+	memcpy(page, desc->ext_compat_id, 8);
+	return 8;
+}
+
+static ssize_t rndis_grp_compatible_id_store(struct usb_os_desc *desc,
+					     const char *page, size_t len)
+{
+	int l;
+
+	l = min_t(int, 8, len);
+	if (page[l - 1] == '\n')
+		--l;
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
+	memcpy(desc->ext_compat_id, page, l);
+	desc->ext_compat_id[l] = '\0';
+
+	if (desc->opts_mutex)
+		mutex_unlock(desc->opts_mutex);
+
+	return len;
+}
+
+static struct usb_os_desc_attribute rndis_grp_attr_compatible_id =
+	__CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR,
+			rndis_grp_compatible_id_show,
+			rndis_grp_compatible_id_store);
+
+static ssize_t rndis_grp_sub_compatible_id_show(struct usb_os_desc *desc,
+						char *page)
+{
+	memcpy(page, desc->ext_compat_id + 8, 8);
+	return 8;
+}
+
+static ssize_t rndis_grp_sub_compatible_id_store(struct usb_os_desc *desc,
+						 const char *page, size_t len)
+{
+	int l;
+
+	l = min_t(int, 8, len);
+	if (page[l - 1] == '\n')
+		--l;
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
+	memcpy(desc->ext_compat_id + 8, page, l);
+	desc->ext_compat_id[l + 8] = '\0';
+
+	if (desc->opts_mutex)
+		mutex_unlock(desc->opts_mutex);
+
+	return len;
+}
+
+static struct usb_os_desc_attribute rndis_grp_attr_sub_compatible_id =
+	__CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR,
+			rndis_grp_sub_compatible_id_show,
+			rndis_grp_sub_compatible_id_store);
+
+static struct configfs_attribute *interf_grp_attrs[] = {
+	&rndis_grp_attr_compatible_id.attr,
+	&rndis_grp_attr_sub_compatible_id.attr,
+	NULL
+};
+
+int usb_os_desc_prepare_interf_dir(struct config_group *parent,
+				   int n_interf,
+				   struct usb_os_desc **desc,
+				   struct module *owner)
+{
+	struct config_group **f_default_groups, *os_desc_group,
+				**interface_groups;
+	struct config_item_type *os_desc_type, *interface_type;
+
+	vla_group(data_chunk);
+	vla_item(data_chunk, struct config_group *, f_default_groups, 2);
+	vla_item(data_chunk, struct config_group, os_desc_group, 1);
+	vla_item(data_chunk, struct config_group *, interface_groups,
+		 n_interf + 1);
+	vla_item(data_chunk, struct config_item_type, os_desc_type, 1);
+	vla_item(data_chunk, struct config_item_type, interface_type, 1);
+
+	char *vlabuf = kzalloc(vla_group_size(data_chunk), GFP_KERNEL);
+	if (!vlabuf)
+		return -ENOMEM;
+
+	f_default_groups = vla_ptr(vlabuf, data_chunk, f_default_groups);
+	os_desc_group = vla_ptr(vlabuf, data_chunk, os_desc_group);
+	os_desc_type = vla_ptr(vlabuf, data_chunk, os_desc_type);
+	interface_groups = vla_ptr(vlabuf, data_chunk, interface_groups);
+	interface_type = vla_ptr(vlabuf, data_chunk, interface_type);
+
+	parent->default_groups = f_default_groups;
+	os_desc_type->ct_owner = owner;
+	config_group_init_type_name(os_desc_group, "os_desc", os_desc_type);
+	f_default_groups[0] = os_desc_group;
+
+	os_desc_group->default_groups = interface_groups;
+	interface_type->ct_item_ops = &interf_item_ops;
+	interface_type->ct_group_ops = &interf_grp_ops;
+	interface_type->ct_attrs = interf_grp_attrs;
+	interface_type->ct_owner = owner;
+
+	while (n_interf--) {
+		struct usb_os_desc *d;
+
+		d = desc[n_interf];
+		d->owner = owner;
+		config_group_init_type_name(&d->group, "", interface_type);
+		config_item_set_name(&d->group.cg_item, "interface.%d",
+				     n_interf);
+		interface_groups[n_interf] = &d->group;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(usb_os_desc_prepare_interf_dir);
+
 static int configfs_do_nothing(struct usb_composite_dev *cdev)
 {
 	WARN_ON(1);
@@ -745,6 +1275,9 @@ static int configfs_do_nothing(struct usb_composite_dev *cdev)
 int composite_dev_prepare(struct usb_composite_driver *composite,
 		struct usb_composite_dev *dev);
 
+int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
+				  struct usb_ep *ep0);
+
 static void purge_configs_funcs(struct gadget_info *gi)
 {
 	struct usb_configuration	*c;
@@ -793,7 +1326,7 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
 	ret = -EINVAL;
 
 	if (list_empty(&gi->cdev.configs)) {
-		pr_err("Need atleast one configuration in %s.\n",
+		pr_err("Need at least one configuration in %s.\n",
 				gi->composite.name);
 		goto err_comp_cleanup;
 	}
@@ -804,7 +1337,7 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
 
 		cfg = container_of(c, struct config_usb_cfg, c);
 		if (list_empty(&cfg->func_list)) {
-			pr_err("Config %s/%d of %s needs atleast one function.\n",
+			pr_err("Config %s/%d of %s needs at least one function.\n",
 			      c->label, c->bConfigurationValue,
 			      gi->composite.name);
 			goto err_comp_cleanup;
@@ -839,6 +1372,12 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
 		gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id;
 	}
 
+	if (gi->use_os_desc) {
+		cdev->use_os_string = true;
+		cdev->b_vendor_code = gi->b_vendor_code;
+		memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
+	}
+
 	/* Go through all configs, attach all functions */
 	list_for_each_entry(c, &gi->cdev.configs, list) {
 		struct config_usb_cfg *cfg;
@@ -874,6 +1413,12 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
 		}
 		usb_ep_autoconfig_reset(cdev->gadget);
 	}
+	if (cdev->use_os_string) {
+		ret = composite_os_desc_req_prepare(cdev, gadget->ep0);
+		if (ret)
+			goto err_purge_funcs;
+	}
+
 	usb_ep_autoconfig_reset(cdev->gadget);
 	return 0;
 
@@ -929,6 +1474,7 @@ static struct config_group *gadgets_make(
 	gi->group.default_groups[0] = &gi->functions_group;
 	gi->group.default_groups[1] = &gi->configs_group;
 	gi->group.default_groups[2] = &gi->strings_group;
+	gi->group.default_groups[3] = &gi->os_desc_group;
 
 	config_group_init_type_name(&gi->functions_group, "functions",
 			&functions_type);
@@ -936,6 +1482,8 @@ static struct config_group *gadgets_make(
 			&config_desc_type);
 	config_group_init_type_name(&gi->strings_group, "strings",
 			&gadget_strings_strings_type);
+	config_group_init_type_name(&gi->os_desc_group, "os_desc",
+			&os_desc_type);
 
 	gi->composite.bind = configfs_do_nothing;
 	gi->composite.unbind = configfs_do_nothing;
@@ -1005,7 +1553,7 @@ void unregister_gadget_item(struct config_item *item)
 
 	unregister_gadget(gi);
 }
-EXPORT_SYMBOL(unregister_gadget_item);
+EXPORT_SYMBOL_GPL(unregister_gadget_item);
 
 static int __init gadget_cfs_init(void)
 {