usb: gadget: always update HS/SS descriptors and create a copy of them

HS and SS descriptors are staticaly created. They are updated during the
bind process with the endpoint address, string id or interface numbers.

After that, the descriptor chain is linked to struct usb_function which
is used by composite in order to serve the GET_DESCRIPTOR requests,
number of available configs and so on.

There is no need to assign the HS descriptor only if the UDC supports
HS speed because composite won't report those to the host if HS support
has not been reached. The same reasoning is valid for SS.

This patch makes sure each function updates HS/SS descriptors
unconditionally and uses the newly introduced helper function to create a
copy the descriptors for the speed which is supported by the UDC.

While at that, also rename f->descriptors to f->fs_descriptors in order
to make it more explicit what that means.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

24 files changed, 307 insertions, 480 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 957f973..2a6bfe7 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -107,7 +107,7 @@ int config_ep_by_speed(struct usb_gadget *g,
 		}
 		/* else: fall through */
 	default:
-		speed_desc = f->descriptors;
+		speed_desc = f->fs_descriptors;
 	}
 	/* find descriptors */
 	for_each_ep_desc(speed_desc, d_spd) {
@@ -200,7 +200,7 @@ int usb_add_function(struct usb_configuration *config,
 	 * as full speed ... it's the function drivers that will need
 	 * to avoid bulk and ISO transfers.
 	 */
-	if (!config->fullspeed && function->descriptors)
+	if (!config->fullspeed && function->fs_descriptors)
 		config->fullspeed = true;
 	if (!config->highspeed && function->hs_descriptors)
 		config->highspeed = true;
@@ -363,7 +363,7 @@ static int config_buf(struct usb_configuration *config,
 			descriptors = f->hs_descriptors;
 			break;
 		default:
-			descriptors = f->descriptors;
+			descriptors = f->fs_descriptors;
 		}
 
 		if (!descriptors)
@@ -620,7 +620,7 @@ static int set_config(struct usb_composite_dev *cdev,
 			descriptors = f->hs_descriptors;
 			break;
 		default:
-			descriptors = f->descriptors;
+			descriptors = f->fs_descriptors;
 		}
 
 		for (; *descriptors; ++descriptors) {
diff --git a/drivers/usb/gadget/config.c b/drivers/usb/gadget/config.c
index e3a9892..34e12fc 100644
--- a/drivers/usb/gadget/config.c
+++ b/drivers/usb/gadget/config.c
@@ -19,7 +19,7 @@
 
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
-
+#include <linux/usb/composite.h>
 
 /**
  * usb_descriptor_fillbuf - fill buffer with descriptors
@@ -158,3 +158,40 @@ usb_copy_descriptors(struct usb_descriptor_header **src)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(usb_copy_descriptors);
+
+int usb_assign_descriptors(struct usb_function *f,
+		struct usb_descriptor_header **fs,
+		struct usb_descriptor_header **hs,
+		struct usb_descriptor_header **ss)
+{
+	struct usb_gadget *g = f->config->cdev->gadget;
+
+	if (fs) {
+		f->fs_descriptors = usb_copy_descriptors(fs);
+		if (!f->fs_descriptors)
+			goto err;
+	}
+	if (hs && gadget_is_dualspeed(g)) {
+		f->hs_descriptors = usb_copy_descriptors(hs);
+		if (!f->hs_descriptors)
+			goto err;
+	}
+	if (ss && gadget_is_superspeed(g)) {
+		f->ss_descriptors = usb_copy_descriptors(ss);
+		if (!f->ss_descriptors)
+			goto err;
+	}
+	return 0;
+err:
+	usb_free_all_descriptors(f);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(usb_assign_descriptors);
+
+void usb_free_all_descriptors(struct usb_function *f)
+{
+	usb_free_descriptors(f->fs_descriptors);
+	usb_free_descriptors(f->hs_descriptors);
+	usb_free_descriptors(f->ss_descriptors);
+}
+EXPORT_SYMBOL_GPL(usb_free_all_descriptors);
diff --git a/drivers/usb/gadget/f_acm.c b/drivers/usb/gadget/f_acm.c
index 7c30bb4..308242b 100644
--- a/drivers/usb/gadget/f_acm.c
+++ b/drivers/usb/gadget/f_acm.c
@@ -658,37 +658,22 @@ acm_bind(struct usb_configuration *c, struct usb_function *f)
 	acm->notify_req->complete = acm_cdc_notify_complete;
 	acm->notify_req->context = acm;
 
-	/* copy descriptors */
-	f->descriptors = usb_copy_descriptors(acm_fs_function);
-	if (!f->descriptors)
-		goto fail;
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		acm_hs_in_desc.bEndpointAddress =
-				acm_fs_in_desc.bEndpointAddress;
-		acm_hs_out_desc.bEndpointAddress =
-				acm_fs_out_desc.bEndpointAddress;
-		acm_hs_notify_desc.bEndpointAddress =
-				acm_fs_notify_desc.bEndpointAddress;
-
-		/* copy descriptors */
-		f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
-	}
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		acm_ss_in_desc.bEndpointAddress =
-			acm_fs_in_desc.bEndpointAddress;
-		acm_ss_out_desc.bEndpointAddress =
-			acm_fs_out_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->ss_descriptors = usb_copy_descriptors(acm_ss_function);
-		if (!f->ss_descriptors)
-			goto fail;
-	}
+	acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
+	acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
+	acm_hs_notify_desc.bEndpointAddress =
+		acm_fs_notify_desc.bEndpointAddress;
+
+	acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
+	acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
+			acm_ss_function);
+	if (status)
+		goto fail;
 
 	DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 			acm->port_num,
@@ -720,11 +705,7 @@ acm_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct f_acm		*acm = func_to_acm(f);
 
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	if (gadget_is_superspeed(c->cdev->gadget))
-		usb_free_descriptors(f->ss_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 	gs_free_req(acm->notify, acm->notify_req);
 	kfree(acm);
 }
diff --git a/drivers/usb/gadget/f_ecm.c b/drivers/usb/gadget/f_ecm.c
index a158740..2d3c5a4 100644
--- a/drivers/usb/gadget/f_ecm.c
+++ b/drivers/usb/gadget/f_ecm.c
@@ -743,42 +743,24 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 	ecm->notify_req->context = ecm;
 	ecm->notify_req->complete = ecm_notify_complete;
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(ecm_fs_function);
-	if (!f->descriptors)
-		goto fail;
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hs_ecm_in_desc.bEndpointAddress =
-				fs_ecm_in_desc.bEndpointAddress;
-		hs_ecm_out_desc.bEndpointAddress =
-				fs_ecm_out_desc.bEndpointAddress;
-		hs_ecm_notify_desc.bEndpointAddress =
-				fs_ecm_notify_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(ecm_hs_function);
-		if (!f->hs_descriptors)
-			goto fail;
-	}
-
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		ss_ecm_in_desc.bEndpointAddress =
-				fs_ecm_in_desc.bEndpointAddress;
-		ss_ecm_out_desc.bEndpointAddress =
-				fs_ecm_out_desc.bEndpointAddress;
-		ss_ecm_notify_desc.bEndpointAddress =
-				fs_ecm_notify_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->ss_descriptors = usb_copy_descriptors(ecm_ss_function);
-		if (!f->ss_descriptors)
-			goto fail;
-	}
+	hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
+	hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
+	hs_ecm_notify_desc.bEndpointAddress =
+		fs_ecm_notify_desc.bEndpointAddress;
+
+	ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
+	ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
+	ss_ecm_notify_desc.bEndpointAddress =
+		fs_ecm_notify_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
+			ecm_ss_function);
+	if (status)
+		goto fail;
 
 	/* NOTE:  all that is done without knowing or caring about
 	 * the network link ... which is unavailable to this code
@@ -796,11 +778,6 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 	return 0;
 
 fail:
-	if (f->descriptors)
-		usb_free_descriptors(f->descriptors);
-	if (f->hs_descriptors)
-		usb_free_descriptors(f->hs_descriptors);
-
 	if (ecm->notify_req) {
 		kfree(ecm->notify_req->buf);
 		usb_ep_free_request(ecm->notify, ecm->notify_req);
@@ -826,11 +803,7 @@ ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	DBG(c->cdev, "ecm unbind\n");
 
-	if (gadget_is_superspeed(c->cdev->gadget))
-		usb_free_descriptors(f->ss_descriptors);
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 
 	kfree(ecm->notify_req->buf);
 	usb_ep_free_request(ecm->notify, ecm->notify_req);
diff --git a/drivers/usb/gadget/f_eem.c b/drivers/usb/gadget/f_eem.c
index a9cf2052..cf0ebee8 100644
--- a/drivers/usb/gadget/f_eem.c
+++ b/drivers/usb/gadget/f_eem.c
@@ -274,38 +274,20 @@ eem_bind(struct usb_configuration *c, struct usb_function *f)
 
 	status = -ENOMEM;
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(eem_fs_function);
-	if (!f->descriptors)
-		goto fail;
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		eem_hs_in_desc.bEndpointAddress =
-				eem_fs_in_desc.bEndpointAddress;
-		eem_hs_out_desc.bEndpointAddress =
-				eem_fs_out_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(eem_hs_function);
-		if (!f->hs_descriptors)
-			goto fail;
-	}
+	eem_hs_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress;
+	eem_hs_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress;
 
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		eem_ss_in_desc.bEndpointAddress =
-				eem_fs_in_desc.bEndpointAddress;
-		eem_ss_out_desc.bEndpointAddress =
-				eem_fs_out_desc.bEndpointAddress;
+	eem_ss_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress;
+	eem_ss_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress;
 
-		/* copy descriptors, and track endpoint copies */
-		f->ss_descriptors = usb_copy_descriptors(eem_ss_function);
-		if (!f->ss_descriptors)
-			goto fail;
-	}
+	status = usb_assign_descriptors(f, eem_fs_function, eem_hs_function,
+			eem_ss_function);
+	if (status)
+		goto fail;
 
 	DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
 			gadget_is_superspeed(c->cdev->gadget) ? "super" :
@@ -314,11 +296,7 @@ eem_bind(struct usb_configuration *c, struct usb_function *f)
 	return 0;
 
 fail:
-	if (f->descriptors)
-		usb_free_descriptors(f->descriptors);
-	if (f->hs_descriptors)
-		usb_free_descriptors(f->hs_descriptors);
-
+	usb_free_all_descriptors(f);
 	if (eem->port.out_ep)
 		eem->port.out_ep->driver_data = NULL;
 	if (eem->port.in_ep)
@@ -336,11 +314,7 @@ eem_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	DBG(c->cdev, "eem unbind\n");
 
-	if (gadget_is_superspeed(c->cdev->gadget))
-		usb_free_descriptors(f->ss_descriptors);
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 	kfree(eem);
 }
 
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 64c4ec1..4a6961c 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -2097,7 +2097,7 @@ static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
 	if (isHS)
 		func->function.hs_descriptors[(long)valuep] = desc;
 	else
-		func->function.descriptors[(long)valuep]    = desc;
+		func->function.fs_descriptors[(long)valuep]    = desc;
 
 	if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
 		return 0;
@@ -2249,7 +2249,7 @@ static int ffs_func_bind(struct usb_configuration *c,
 	 * numbers without worrying that it may be described later on.
 	 */
 	if (likely(full)) {
-		func->function.descriptors = data->fs_descs;
+		func->function.fs_descriptors = data->fs_descs;
 		ret = ffs_do_descs(ffs->fs_descs_count,
 				   data->raw_descs,
 				   sizeof data->raw_descs,
diff --git a/drivers/usb/gadget/f_hid.c b/drivers/usb/gadget/f_hid.c
index 511e527..6e69a8e 100644
--- a/drivers/usb/gadget/f_hid.c
+++ b/drivers/usb/gadget/f_hid.c
@@ -573,7 +573,6 @@ static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
 		goto fail;
 	hidg_interface_desc.bInterfaceNumber = status;
 
-
 	/* allocate instance-specific endpoints */
 	status = -ENODEV;
 	ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
@@ -609,20 +608,15 @@ static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
 	hidg_desc.desc[0].wDescriptorLength =
 		cpu_to_le16(hidg->report_desc_length);
 
-	/* copy descriptors */
-	f->descriptors = usb_copy_descriptors(hidg_fs_descriptors);
-	if (!f->descriptors)
-		goto fail;
+	hidg_hs_in_ep_desc.bEndpointAddress =
+		hidg_fs_in_ep_desc.bEndpointAddress;
+	hidg_hs_out_ep_desc.bEndpointAddress =
+		hidg_fs_out_ep_desc.bEndpointAddress;
 
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hidg_hs_in_ep_desc.bEndpointAddress =
-			hidg_fs_in_ep_desc.bEndpointAddress;
-		hidg_hs_out_ep_desc.bEndpointAddress =
-			hidg_fs_out_ep_desc.bEndpointAddress;
-		f->hs_descriptors = usb_copy_descriptors(hidg_hs_descriptors);
-		if (!f->hs_descriptors)
-			goto fail;
-	}
+	status = usb_assign_descriptors(f, hidg_fs_descriptors,
+			hidg_hs_descriptors, NULL);
+	if (status)
+		goto fail;
 
 	mutex_init(&hidg->lock);
 	spin_lock_init(&hidg->spinlock);
@@ -649,9 +643,7 @@ fail:
 			usb_ep_free_request(hidg->in_ep, hidg->req);
 	}
 
-	usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
-
+	usb_free_all_descriptors(f);
 	return status;
 }
 
@@ -668,9 +660,7 @@ static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 	kfree(hidg->req->buf);
 	usb_ep_free_request(hidg->in_ep, hidg->req);
 
-	/* free descriptors copies */
-	usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 
 	kfree(hidg->report_desc);
 	kfree(hidg);
diff --git a/drivers/usb/gadget/f_loopback.c b/drivers/usb/gadget/f_loopback.c
index 7275706..bb39cb2 100644
--- a/drivers/usb/gadget/f_loopback.c
+++ b/drivers/usb/gadget/f_loopback.c
@@ -177,6 +177,7 @@ loopback_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_composite_dev *cdev = c->cdev;
 	struct f_loopback	*loop = func_to_loop(f);
 	int			id;
+	int ret;
 
 	/* allocate interface ID(s) */
 	id = usb_interface_id(c, f);
@@ -201,22 +202,19 @@ autoconf_fail:
 	loop->out_ep->driver_data = cdev;	/* claim */
 
 	/* support high speed hardware */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hs_loop_source_desc.bEndpointAddress =
-				fs_loop_source_desc.bEndpointAddress;
-		hs_loop_sink_desc.bEndpointAddress =
-				fs_loop_sink_desc.bEndpointAddress;
-		f->hs_descriptors = hs_loopback_descs;
-	}
+	hs_loop_source_desc.bEndpointAddress =
+		fs_loop_source_desc.bEndpointAddress;
+	hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
 
 	/* support super speed hardware */
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		ss_loop_source_desc.bEndpointAddress =
-				fs_loop_source_desc.bEndpointAddress;
-		ss_loop_sink_desc.bEndpointAddress =
-				fs_loop_sink_desc.bEndpointAddress;
-		f->ss_descriptors = ss_loopback_descs;
-	}
+	ss_loop_source_desc.bEndpointAddress =
+		fs_loop_source_desc.bEndpointAddress;
+	ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
+
+	ret = usb_assign_descriptors(f, fs_loopback_descs, hs_loopback_descs,
+			ss_loopback_descs);
+	if (ret)
+		return ret;
 
 	DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
 	    (gadget_is_superspeed(c->cdev->gadget) ? "super" :
@@ -228,6 +226,7 @@ autoconf_fail:
 static void
 loopback_unbind(struct usb_configuration *c, struct usb_function *f)
 {
+	usb_free_all_descriptors(f);
 	kfree(func_to_loop(f));
 }
 
@@ -379,7 +378,6 @@ static int __init loopback_bind_config(struct usb_configuration *c)
 		return -ENOMEM;
 
 	loop->function.name = "loopback";
-	loop->function.descriptors = fs_loopback_descs;
 	loop->function.bind = loopback_bind;
 	loop->function.unbind = loopback_unbind;
 	loop->function.set_alt = loopback_set_alt;
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 3a7668b..3433e43 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -2904,9 +2904,7 @@ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
 	}
 
 	fsg_common_put(common);
-	usb_free_descriptors(fsg->function.descriptors);
-	usb_free_descriptors(fsg->function.hs_descriptors);
-	usb_free_descriptors(fsg->function.ss_descriptors);
+	usb_free_all_descriptors(&fsg->function);
 	kfree(fsg);
 }
 
@@ -2916,6 +2914,8 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_gadget	*gadget = c->cdev->gadget;
 	int			i;
 	struct usb_ep		*ep;
+	unsigned		max_burst;
+	int			ret;
 
 	fsg->gadget = gadget;
 
@@ -2939,45 +2939,27 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
 	ep->driver_data = fsg->common;	/* claim the endpoint */
 	fsg->bulk_out = ep;
 
-	/* Copy descriptors */
-	f->descriptors = usb_copy_descriptors(fsg_fs_function);
-	if (unlikely(!f->descriptors))
-		return -ENOMEM;
-
-	if (gadget_is_dualspeed(gadget)) {
-		/* Assume endpoint addresses are the same for both speeds */
-		fsg_hs_bulk_in_desc.bEndpointAddress =
-			fsg_fs_bulk_in_desc.bEndpointAddress;
-		fsg_hs_bulk_out_desc.bEndpointAddress =
-			fsg_fs_bulk_out_desc.bEndpointAddress;
-		f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
-		if (unlikely(!f->hs_descriptors)) {
-			usb_free_descriptors(f->descriptors);
-			return -ENOMEM;
-		}
-	}
-
-	if (gadget_is_superspeed(gadget)) {
-		unsigned	max_burst;
+	/* Assume endpoint addresses are the same for both speeds */
+	fsg_hs_bulk_in_desc.bEndpointAddress =
+		fsg_fs_bulk_in_desc.bEndpointAddress;
+	fsg_hs_bulk_out_desc.bEndpointAddress =
+		fsg_fs_bulk_out_desc.bEndpointAddress;
 
-		/* Calculate bMaxBurst, we know packet size is 1024 */
-		max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
+	/* Calculate bMaxBurst, we know packet size is 1024 */
+	max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
 
-		fsg_ss_bulk_in_desc.bEndpointAddress =
-			fsg_fs_bulk_in_desc.bEndpointAddress;
-		fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
+	fsg_ss_bulk_in_desc.bEndpointAddress =
+		fsg_fs_bulk_in_desc.bEndpointAddress;
+	fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
 
-		fsg_ss_bulk_out_desc.bEndpointAddress =
-			fsg_fs_bulk_out_desc.bEndpointAddress;
-		fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
+	fsg_ss_bulk_out_desc.bEndpointAddress =
+		fsg_fs_bulk_out_desc.bEndpointAddress;
+	fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
 
-		f->ss_descriptors = usb_copy_descriptors(fsg_ss_function);
-		if (unlikely(!f->ss_descriptors)) {
-			usb_free_descriptors(f->hs_descriptors);
-			usb_free_descriptors(f->descriptors);
-			return -ENOMEM;
-		}
-	}
+	ret = usb_assign_descriptors(f, fsg_fs_function, fsg_hs_function,
+			fsg_ss_function);
+	if (ret)
+		goto autoconf_fail;
 
 	return 0;
 
@@ -2986,7 +2968,6 @@ autoconf_fail:
 	return -ENOTSUPP;
 }
 
-
 /****************************** ADD FUNCTION ******************************/
 
 static struct usb_gadget_strings *fsg_strings_array[] = {
diff --git a/drivers/usb/gadget/f_midi.c b/drivers/usb/gadget/f_midi.c
index b265ee8..263e721 100644
--- a/drivers/usb/gadget/f_midi.c
+++ b/drivers/usb/gadget/f_midi.c
@@ -414,8 +414,7 @@ static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
 	kfree(midi->id);
 	midi->id = NULL;
 
-	usb_free_descriptors(f->descriptors);
-	usb_free_descriptors(f->hs_descriptors);
+	usb_free_all_descriptors(f);
 	kfree(midi);
 }
 
@@ -882,9 +881,10 @@ f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 	 * both speeds
 	 */
 	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(midi_function);
-	if (!f->descriptors)
+	f->fs_descriptors = usb_copy_descriptors(midi_function);
+	if (!f->fs_descriptors)
 		goto fail_f_midi;
+
 	if (gadget_is_dualspeed(c->cdev->gadget)) {
 		bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
 		bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c
index 424fc3d..326d7e6 100644
--- a/drivers/usb/gadget/f_ncm.c
+++ b/drivers/usb/gadget/f_ncm.c
@@ -1208,30 +1208,18 @@ ncm_bind(struct usb_configuration *c, struct usb_function *f)
 	ncm->notify_req->context = ncm;
 	ncm->notify_req->complete = ncm_notify_complete;
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(ncm_fs_function);
-	if (!f->descriptors)
-		goto fail;
-
 	/*
 	 * support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hs_ncm_in_desc.bEndpointAddress =
-				fs_ncm_in_desc.bEndpointAddress;
-		hs_ncm_out_desc.bEndpointAddress =
-				fs_ncm_out_desc.bEndpointAddress;
-		hs_ncm_notify_desc.bEndpointAddress =
-				fs_ncm_notify_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(ncm_hs_function);
-		if (!f->hs_descriptors)
-			goto fail;
-	}
+	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
+	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
+	hs_ncm_notify_desc.bEndpointAddress =
+		fs_ncm_notify_desc.bEndpointAddress;
 
+	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
+			NULL);
 	/*
 	 * NOTE:  all that is done without knowing or caring about
 	 * the network link ... which is unavailable to this code
@@ -1248,9 +1236,7 @@ ncm_bind(struct usb_configuration *c, struct usb_function *f)
 	return 0;
 
 fail:
-	if (f->descriptors)
-		usb_free_descriptors(f->descriptors);
-
+	usb_free_all_descriptors(f);
 	if (ncm->notify_req) {
 		kfree(ncm->notify_req->buf);
 		usb_ep_free_request(ncm->notify, ncm->notify_req);
@@ -1276,9 +1262,7 @@ ncm_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	DBG(c->cdev, "ncm unbind\n");
 
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 
 	kfree(ncm->notify_req->buf);
 	usb_ep_free_request(ncm->notify, ncm->notify_req);
diff --git a/drivers/usb/gadget/f_obex.c b/drivers/usb/gadget/f_obex.c
index 5f400f6..d74491a 100644
--- a/drivers/usb/gadget/f_obex.c
+++ b/drivers/usb/gadget/f_obex.c
@@ -331,23 +331,19 @@ obex_bind(struct usb_configuration *c, struct usb_function *f)
 	obex->port.out = ep;
 	ep->driver_data = cdev;	/* claim */
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(fs_function);
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
 
-		obex_hs_ep_in_desc.bEndpointAddress =
-				obex_fs_ep_in_desc.bEndpointAddress;
-		obex_hs_ep_out_desc.bEndpointAddress =
-				obex_fs_ep_out_desc.bEndpointAddress;
+	obex_hs_ep_in_desc.bEndpointAddress =
+		obex_fs_ep_in_desc.bEndpointAddress;
+	obex_hs_ep_out_desc.bEndpointAddress =
+		obex_fs_ep_out_desc.bEndpointAddress;
 
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(hs_function);
-	}
+	status = usb_assign_descriptors(f, fs_function, hs_function, NULL);
+	if (status)
+		goto fail;
 
 	/* Avoid letting this gadget enumerate until the userspace
 	 * OBEX server is active.
@@ -368,6 +364,7 @@ obex_bind(struct usb_configuration *c, struct usb_function *f)
 	return 0;
 
 fail:
+	usb_free_all_descriptors(f);
 	/* we might as well release our claims on endpoints */
 	if (obex->port.out)
 		obex->port.out->driver_data = NULL;
@@ -382,9 +379,7 @@ fail:
 static void
 obex_unbind(struct usb_configuration *c, struct usb_function *f)
 {
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 	kfree(func_to_obex(f));
 }
 
diff --git a/drivers/usb/gadget/f_phonet.c b/drivers/usb/gadget/f_phonet.c
index a6c19a4..b21ab55 100644
--- a/drivers/usb/gadget/f_phonet.c
+++ b/drivers/usb/gadget/f_phonet.c
@@ -515,14 +515,14 @@ int pn_bind(struct usb_configuration *c, struct usb_function *f)
 	fp->in_ep = ep;
 	ep->driver_data = fp; /* Claim */
 
-	pn_hs_sink_desc.bEndpointAddress =
-		pn_fs_sink_desc.bEndpointAddress;
-	pn_hs_source_desc.bEndpointAddress =
-		pn_fs_source_desc.bEndpointAddress;
+	pn_hs_sink_desc.bEndpointAddress = pn_fs_sink_desc.bEndpointAddress;
+	pn_hs_source_desc.bEndpointAddress = pn_fs_source_desc.bEndpointAddress;
 
 	/* Do not try to bind Phonet twice... */
-	fp->function.descriptors = fs_pn_function;
-	fp->function.hs_descriptors = hs_pn_function;
+	status = usb_assign_descriptors(f, fs_pn_function, hs_pn_function,
+			NULL);
+	if (status)
+		goto err;
 
 	/* Incoming USB requests */
 	status = -ENOMEM;
@@ -551,7 +551,7 @@ err_req:
 	for (i = 0; i < phonet_rxq_size && fp->out_reqv[i]; i++)
 		usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
 err:
-
+	usb_free_all_descriptors(f);
 	if (fp->out_ep)
 		fp->out_ep->driver_data = NULL;
 	if (fp->in_ep)
@@ -573,6 +573,7 @@ pn_unbind(struct usb_configuration *c, struct usb_function *f)
 		if (fp->out_reqv[i])
 			usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
 
+	usb_free_all_descriptors(f);
 	kfree(fp);
 }
 
diff --git a/drivers/usb/gadget/f_rndis.c b/drivers/usb/gadget/f_rndis.c
index 7c27626..e7c2510 100644
--- a/drivers/usb/gadget/f_rndis.c
+++ b/drivers/usb/gadget/f_rndis.c
@@ -722,42 +722,22 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
 	rndis->notify_req->context = rndis;
 	rndis->notify_req->complete = rndis_response_complete;
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(eth_fs_function);
-	if (!f->descriptors)
-		goto fail;
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hs_in_desc.bEndpointAddress =
-				fs_in_desc.bEndpointAddress;
-		hs_out_desc.bEndpointAddress =
-				fs_out_desc.bEndpointAddress;
-		hs_notify_desc.bEndpointAddress =
-				fs_notify_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(eth_hs_function);
-		if (!f->hs_descriptors)
-			goto fail;
-	}
+	hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
+	hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
+	hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		ss_in_desc.bEndpointAddress =
-				fs_in_desc.bEndpointAddress;
-		ss_out_desc.bEndpointAddress =
-				fs_out_desc.bEndpointAddress;
-		ss_notify_desc.bEndpointAddress =
-				fs_notify_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->ss_descriptors = usb_copy_descriptors(eth_ss_function);
-		if (!f->ss_descriptors)
-			goto fail;
-	}
+	ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
+	ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
+	ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
+			eth_ss_function);
+	if (status)
+		goto fail;
 
 	rndis->port.open = rndis_open;
 	rndis->port.close = rndis_close;
@@ -788,12 +768,7 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
 	return 0;
 
 fail:
-	if (gadget_is_superspeed(c->cdev->gadget) && f->ss_descriptors)
-		usb_free_descriptors(f->ss_descriptors);
-	if (gadget_is_dualspeed(c->cdev->gadget) && f->hs_descriptors)
-		usb_free_descriptors(f->hs_descriptors);
-	if (f->descriptors)
-		usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 
 	if (rndis->notify_req) {
 		kfree(rndis->notify_req->buf);
@@ -822,11 +797,7 @@ rndis_unbind(struct usb_configuration *c, struct usb_function *f)
 	rndis_exit();
 	rndis_string_defs[0].id = 0;
 
-	if (gadget_is_superspeed(c->cdev->gadget))
-		usb_free_descriptors(f->ss_descriptors);
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 
 	kfree(rndis->notify_req->buf);
 	usb_ep_free_request(rndis->notify, rndis->notify_req);
diff --git a/drivers/usb/gadget/f_serial.c b/drivers/usb/gadget/f_serial.c
index 07197d6..98fa779 100644
--- a/drivers/usb/gadget/f_serial.c
+++ b/drivers/usb/gadget/f_serial.c
@@ -213,34 +213,20 @@ gser_bind(struct usb_configuration *c, struct usb_function *f)
 	gser->port.out = ep;
 	ep->driver_data = cdev;	/* claim */
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(gser_fs_function);
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		gser_hs_in_desc.bEndpointAddress =
-				gser_fs_in_desc.bEndpointAddress;
-		gser_hs_out_desc.bEndpointAddress =
-				gser_fs_out_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(gser_hs_function);
-	}
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		gser_ss_in_desc.bEndpointAddress =
-			gser_fs_in_desc.bEndpointAddress;
-		gser_ss_out_desc.bEndpointAddress =
-			gser_fs_out_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->ss_descriptors = usb_copy_descriptors(gser_ss_function);
-		if (!f->ss_descriptors)
-			goto fail;
-	}
+	gser_hs_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
+	gser_hs_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
 
+	gser_ss_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
+	gser_ss_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, gser_fs_function, gser_hs_function,
+			gser_ss_function);
+	if (status)
+		goto fail;
 	DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
 			gser->port_num,
 			gadget_is_superspeed(c->cdev->gadget) ? "super" :
@@ -263,11 +249,7 @@ fail:
 static void
 gser_unbind(struct usb_configuration *c, struct usb_function *f)
 {
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	if (gadget_is_superspeed(c->cdev->gadget))
-		usb_free_descriptors(f->ss_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 	kfree(func_to_gser(f));
 }
 
diff --git a/drivers/usb/gadget/f_sourcesink.c b/drivers/usb/gadget/f_sourcesink.c
index 3c126fd..102d49b 100644
--- a/drivers/usb/gadget/f_sourcesink.c
+++ b/drivers/usb/gadget/f_sourcesink.c
@@ -319,6 +319,7 @@ sourcesink_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_composite_dev *cdev = c->cdev;
 	struct f_sourcesink	*ss = func_to_ss(f);
 	int	id;
+	int ret;
 
 	/* allocate interface ID(s) */
 	id = usb_interface_id(c, f);
@@ -387,64 +388,57 @@ no_iso:
 		isoc_maxpacket = 1024;
 
 	/* support high speed hardware */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hs_source_desc.bEndpointAddress =
-				fs_source_desc.bEndpointAddress;
-		hs_sink_desc.bEndpointAddress =
-				fs_sink_desc.bEndpointAddress;
+	hs_source_desc.bEndpointAddress = fs_source_desc.bEndpointAddress;
+	hs_sink_desc.bEndpointAddress = fs_sink_desc.bEndpointAddress;
 
-		/*
-		 * Fill in the HS isoc descriptors from the module parameters.
-		 * We assume that the user knows what they are doing and won't
-		 * give parameters that their UDC doesn't support.
-		 */
-		hs_iso_source_desc.wMaxPacketSize = isoc_maxpacket;
-		hs_iso_source_desc.wMaxPacketSize |= isoc_mult << 11;
-		hs_iso_source_desc.bInterval = isoc_interval;
-		hs_iso_source_desc.bEndpointAddress =
-				fs_iso_source_desc.bEndpointAddress;
-
-		hs_iso_sink_desc.wMaxPacketSize = isoc_maxpacket;
-		hs_iso_sink_desc.wMaxPacketSize |= isoc_mult << 11;
-		hs_iso_sink_desc.bInterval = isoc_interval;
-		hs_iso_sink_desc.bEndpointAddress =
-				fs_iso_sink_desc.bEndpointAddress;
-
-		f->hs_descriptors = hs_source_sink_descs;
-	}
+	/*
+	 * Fill in the HS isoc descriptors from the module parameters.
+	 * We assume that the user knows what they are doing and won't
+	 * give parameters that their UDC doesn't support.
+	 */
+	hs_iso_source_desc.wMaxPacketSize = isoc_maxpacket;
+	hs_iso_source_desc.wMaxPacketSize |= isoc_mult << 11;
+	hs_iso_source_desc.bInterval = isoc_interval;
+	hs_iso_source_desc.bEndpointAddress =
+		fs_iso_source_desc.bEndpointAddress;
+
+	hs_iso_sink_desc.wMaxPacketSize = isoc_maxpacket;
+	hs_iso_sink_desc.wMaxPacketSize |= isoc_mult << 11;
+	hs_iso_sink_desc.bInterval = isoc_interval;
+	hs_iso_sink_desc.bEndpointAddress = fs_iso_sink_desc.bEndpointAddress;
 
 	/* support super speed hardware */
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		ss_source_desc.bEndpointAddress =
-				fs_source_desc.bEndpointAddress;
-		ss_sink_desc.bEndpointAddress =
-				fs_sink_desc.bEndpointAddress;
+	ss_source_desc.bEndpointAddress =
+		fs_source_desc.bEndpointAddress;
+	ss_sink_desc.bEndpointAddress =
+		fs_sink_desc.bEndpointAddress;
 
-		/*
-		 * Fill in the SS isoc descriptors from the module parameters.
-		 * We assume that the user knows what they are doing and won't
-		 * give parameters that their UDC doesn't support.
-		 */
-		ss_iso_source_desc.wMaxPacketSize = isoc_maxpacket;
-		ss_iso_source_desc.bInterval = isoc_interval;
-		ss_iso_source_comp_desc.bmAttributes = isoc_mult;
-		ss_iso_source_comp_desc.bMaxBurst = isoc_maxburst;
-		ss_iso_source_comp_desc.wBytesPerInterval =
-			isoc_maxpacket * (isoc_mult + 1) * (isoc_maxburst + 1);
-		ss_iso_source_desc.bEndpointAddress =
-				fs_iso_source_desc.bEndpointAddress;
-
-		ss_iso_sink_desc.wMaxPacketSize = isoc_maxpacket;
-		ss_iso_sink_desc.bInterval = isoc_interval;
-		ss_iso_sink_comp_desc.bmAttributes = isoc_mult;
-		ss_iso_sink_comp_desc.bMaxBurst = isoc_maxburst;
-		ss_iso_sink_comp_desc.wBytesPerInterval =
-			isoc_maxpacket * (isoc_mult + 1) * (isoc_maxburst + 1);
-		ss_iso_sink_desc.bEndpointAddress =
-				fs_iso_sink_desc.bEndpointAddress;
-
-		f->ss_descriptors = ss_source_sink_descs;
-	}
+	/*
+	 * Fill in the SS isoc descriptors from the module parameters.
+	 * We assume that the user knows what they are doing and won't
+	 * give parameters that their UDC doesn't support.
+	 */
+	ss_iso_source_desc.wMaxPacketSize = isoc_maxpacket;
+	ss_iso_source_desc.bInterval = isoc_interval;
+	ss_iso_source_comp_desc.bmAttributes = isoc_mult;
+	ss_iso_source_comp_desc.bMaxBurst = isoc_maxburst;
+	ss_iso_source_comp_desc.wBytesPerInterval =
+		isoc_maxpacket * (isoc_mult + 1) * (isoc_maxburst + 1);
+	ss_iso_source_desc.bEndpointAddress =
+		fs_iso_source_desc.bEndpointAddress;
+
+	ss_iso_sink_desc.wMaxPacketSize = isoc_maxpacket;
+	ss_iso_sink_desc.bInterval = isoc_interval;
+	ss_iso_sink_comp_desc.bmAttributes = isoc_mult;
+	ss_iso_sink_comp_desc.bMaxBurst = isoc_maxburst;
+	ss_iso_sink_comp_desc.wBytesPerInterval =
+		isoc_maxpacket * (isoc_mult + 1) * (isoc_maxburst + 1);
+	ss_iso_sink_desc.bEndpointAddress = fs_iso_sink_desc.bEndpointAddress;
+
+	ret = usb_assign_descriptors(f, fs_source_sink_descs,
+			hs_source_sink_descs, ss_source_sink_descs);
+	if (ret)
+		return ret;
 
 	DBG(cdev, "%s speed %s: IN/%s, OUT/%s, ISO-IN/%s, ISO-OUT/%s\n",
 	    (gadget_is_superspeed(c->cdev->gadget) ? "super" :
@@ -458,6 +452,7 @@ no_iso:
 static void
 sourcesink_unbind(struct usb_configuration *c, struct usb_function *f)
 {
+	usb_free_all_descriptors(f);
 	kfree(func_to_ss(f));
 }
 
@@ -773,7 +768,6 @@ static int __init sourcesink_bind_config(struct usb_configuration *c)
 		return -ENOMEM;
 
 	ss->function.name = "source/sink";
-	ss->function.descriptors = fs_source_sink_descs;
 	ss->function.bind = sourcesink_bind;
 	ss->function.unbind = sourcesink_unbind;
 	ss->function.set_alt = sourcesink_set_alt;
diff --git a/drivers/usb/gadget/f_subset.c b/drivers/usb/gadget/f_subset.c
index deb437c..856dbae 100644
--- a/drivers/usb/gadget/f_subset.c
+++ b/drivers/usb/gadget/f_subset.c
@@ -319,38 +319,22 @@ geth_bind(struct usb_configuration *c, struct usb_function *f)
 	geth->port.out_ep = ep;
 	ep->driver_data = cdev;	/* claim */
 
-	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(fs_eth_function);
-	if (!f->descriptors)
-		goto fail;
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		hs_subset_in_desc.bEndpointAddress =
-				fs_subset_in_desc.bEndpointAddress;
-		hs_subset_out_desc.bEndpointAddress =
-				fs_subset_out_desc.bEndpointAddress;
-
-		/* copy descriptors, and track endpoint copies */
-		f->hs_descriptors = usb_copy_descriptors(hs_eth_function);
-		if (!f->hs_descriptors)
-			goto fail;
-	}
+	hs_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
+	hs_subset_out_desc.bEndpointAddress =
+		fs_subset_out_desc.bEndpointAddress;
 
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		ss_subset_in_desc.bEndpointAddress =
-				fs_subset_in_desc.bEndpointAddress;
-		ss_subset_out_desc.bEndpointAddress =
-				fs_subset_out_desc.bEndpointAddress;
+	ss_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
+	ss_subset_out_desc.bEndpointAddress =
+		fs_subset_out_desc.bEndpointAddress;
 
-		/* copy descriptors, and track endpoint copies */
-		f->ss_descriptors = usb_copy_descriptors(ss_eth_function);
-		if (!f->ss_descriptors)
-			goto fail;
-	}
+	status = usb_assign_descriptors(f, fs_eth_function, hs_eth_function,
+			ss_eth_function);
+	if (status)
+		goto fail;
 
 	/* NOTE:  all that is done without knowing or caring about
 	 * the network link ... which is unavailable to this code
@@ -364,11 +348,7 @@ geth_bind(struct usb_configuration *c, struct usb_function *f)
 	return 0;
 
 fail:
-	if (f->descriptors)
-		usb_free_descriptors(f->descriptors);
-	if (f->hs_descriptors)
-		usb_free_descriptors(f->hs_descriptors);
-
+	usb_free_all_descriptors(f);
 	/* we might as well release our claims on endpoints */
 	if (geth->port.out_ep)
 		geth->port.out_ep->driver_data = NULL;
@@ -383,11 +363,7 @@ fail:
 static void
 geth_unbind(struct usb_configuration *c, struct usb_function *f)
 {
-	if (gadget_is_superspeed(c->cdev->gadget))
-		usb_free_descriptors(f->ss_descriptors);
-	if (gadget_is_dualspeed(c->cdev->gadget))
-		usb_free_descriptors(f->hs_descriptors);
-	usb_free_descriptors(f->descriptors);
+	usb_free_all_descriptors(f);
 	geth_string_defs[1].s = NULL;
 	kfree(func_to_geth(f));
 }
diff --git a/drivers/usb/gadget/f_uac1.c b/drivers/usb/gadget/f_uac1.c
index c8ed41b..f570e66 100644
--- a/drivers/usb/gadget/f_uac1.c
+++ b/drivers/usb/gadget/f_uac1.c
@@ -630,7 +630,7 @@ f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_composite_dev *cdev = c->cdev;
 	struct f_audio		*audio = func_to_audio(f);
 	int			status;
-	struct usb_ep		*ep;
+	struct usb_ep		*ep = NULL;
 
 	f_audio_build_desc(audio);
 
@@ -659,21 +659,14 @@ f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 	status = -ENOMEM;
 
 	/* copy descriptors, and track endpoint copies */
-	f->descriptors = usb_copy_descriptors(f_audio_desc);
-
-	/*
-	 * support all relevant hardware speeds... we expect that when
-	 * hardware is dual speed, all bulk-capable endpoints work at
-	 * both speeds
-	 */
-	if (gadget_is_dualspeed(c->cdev->gadget)) {
-		f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
-	}
-
+	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL);
+	if (status)
+		goto fail;
 	return 0;
 
 fail:
-
+	if (ep)
+		ep->driver_data = NULL;
 	return status;
 }
 
@@ -682,8 +675,7 @@ f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct f_audio		*audio = func_to_audio(f);
 
-	usb_free_descriptors(f->descriptors);
-	usb_free_descriptors(f->hs_descriptors);
+	usb_free_all_descriptors(f);
 	kfree(audio);
 }
 
diff --git a/drivers/usb/gadget/f_uac2.c b/drivers/usb/gadget/f_uac2.c
index f02b8ec..730a260 100644
--- a/drivers/usb/gadget/f_uac2.c
+++ b/drivers/usb/gadget/f_uac2.c
@@ -998,9 +998,9 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
 	hs_epin_desc.wMaxPacketSize = fs_epin_desc.wMaxPacketSize;
 
-	fn->descriptors = usb_copy_descriptors(fs_audio_desc);
-	if (gadget_is_dualspeed(gadget))
-		fn->hs_descriptors = usb_copy_descriptors(hs_audio_desc);
+	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL);
+	if (ret)
+		goto err;
 
 	prm = &agdev->uac2.c_prm;
 	prm->max_psize = hs_epout_desc.wMaxPacketSize;
@@ -1029,8 +1029,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
 err:
 	kfree(agdev->uac2.p_prm.rbuf);
 	kfree(agdev->uac2.c_prm.rbuf);
-	usb_free_descriptors(fn->hs_descriptors);
-	usb_free_descriptors(fn->descriptors);
+	usb_free_all_descriptors(fn);
 	if (agdev->in_ep)
 		agdev->in_ep->driver_data = NULL;
 	if (agdev->out_ep)
@@ -1042,8 +1041,6 @@ static void
 afunc_unbind(struct usb_configuration *cfg, struct usb_function *fn)
 {
 	struct audio_dev *agdev = func_to_agdev(fn);
-	struct usb_composite_dev *cdev = cfg->cdev;
-	struct usb_gadget *gadget = cdev->gadget;
 	struct uac2_rtd_params *prm;
 
 	alsa_uac2_exit(agdev);
@@ -1053,10 +1050,7 @@ afunc_unbind(struct usb_configuration *cfg, struct usb_function *fn)
 
 	prm = &agdev->uac2.c_prm;
 	kfree(prm->rbuf);
-
-	if (gadget_is_dualspeed(gadget))
-		usb_free_descriptors(fn->hs_descriptors);
-	usb_free_descriptors(fn->descriptors);
+	usb_free_all_descriptors(fn);
 
 	if (agdev->in_ep)
 		agdev->in_ep->driver_data = NULL;
diff --git a/drivers/usb/gadget/f_uvc.c b/drivers/usb/gadget/f_uvc.c
index 10f13c1..28ff254 100644
--- a/drivers/usb/gadget/f_uvc.c
+++ b/drivers/usb/gadget/f_uvc.c
@@ -583,9 +583,7 @@ uvc_function_unbind(struct usb_configuration *c, struct usb_function *f)
 	usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
 	kfree(uvc->control_buf);
 
-	kfree(f->descriptors);
-	kfree(f->hs_descriptors);
-	kfree(f->ss_descriptors);
+	usb_free_all_descriptors(f);
 
 	kfree(uvc);
 }
@@ -651,49 +649,40 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	/* sanity check the streaming endpoint module parameters */
 	if (streaming_maxpacket > 1024)
 		streaming_maxpacket = 1024;
+	/*
+	 * Fill in the HS descriptors from the module parameters for the Video
+	 * Streaming endpoint.
+	 * NOTE: We assume that the user knows what they are doing and won't
+	 * give parameters that their UDC doesn't support.
+	 */
+	uvc_hs_streaming_ep.wMaxPacketSize = streaming_maxpacket;
+	uvc_hs_streaming_ep.wMaxPacketSize |= streaming_mult << 11;
+	uvc_hs_streaming_ep.bInterval = streaming_interval;
+	uvc_hs_streaming_ep.bEndpointAddress =
+		uvc_fs_streaming_ep.bEndpointAddress;
 
-	/* Copy descriptors for FS. */
-	f->descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
-
-	/* support high speed hardware */
-	if (gadget_is_dualspeed(cdev->gadget)) {
-		/*
-		 * Fill in the HS descriptors from the module parameters for the
-		 * Video Streaming endpoint.
-		 * NOTE: We assume that the user knows what they are doing and
-		 * won't give parameters that their UDC doesn't support.
-		 */
-		uvc_hs_streaming_ep.wMaxPacketSize = streaming_maxpacket;
-		uvc_hs_streaming_ep.wMaxPacketSize |= streaming_mult << 11;
-		uvc_hs_streaming_ep.bInterval = streaming_interval;
-		uvc_hs_streaming_ep.bEndpointAddress =
-				uvc_fs_streaming_ep.bEndpointAddress;
-
-		/* Copy descriptors. */
-		f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
-	}
+	/*
+	 * Fill in the SS descriptors from the module parameters for the Video
+	 * Streaming endpoint.
+	 * NOTE: We assume that the user knows what they are doing and won't
+	 * give parameters that their UDC doesn't support.
+	 */
+	uvc_ss_streaming_ep.wMaxPacketSize = streaming_maxpacket;
+	uvc_ss_streaming_ep.bInterval = streaming_interval;
+	uvc_ss_streaming_comp.bmAttributes = streaming_mult;
+	uvc_ss_streaming_comp.bMaxBurst = streaming_maxburst;
+	uvc_ss_streaming_comp.wBytesPerInterval =
+		streaming_maxpacket * (streaming_mult + 1) *
+		(streaming_maxburst + 1);
+	uvc_ss_streaming_ep.bEndpointAddress =
+		uvc_fs_streaming_ep.bEndpointAddress;
 
-	/* support super speed hardware */
-	if (gadget_is_superspeed(c->cdev->gadget)) {
-		/*
-		 * Fill in the SS descriptors from the module parameters for the
-		 * Video Streaming endpoint.
-		 * NOTE: We assume that the user knows what they are doing and
-		 * won't give parameters that their UDC doesn't support.
-		 */
-		uvc_ss_streaming_ep.wMaxPacketSize = streaming_maxpacket;
-		uvc_ss_streaming_ep.bInterval = streaming_interval;
-		uvc_ss_streaming_comp.bmAttributes = streaming_mult;
-		uvc_ss_streaming_comp.bMaxBurst = streaming_maxburst;
-		uvc_ss_streaming_comp.wBytesPerInterval =
-			streaming_maxpacket * (streaming_mult + 1) *
-			(streaming_maxburst + 1);
-		uvc_ss_streaming_ep.bEndpointAddress =
-				uvc_fs_streaming_ep.bEndpointAddress;
-
-		/* Copy descriptors. */
+	/* Copy descriptors */
+	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
+	if (gadget_is_dualspeed(cdev->gadget))
+		f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
+	if (gadget_is_superspeed(c->cdev->gadget))
 		f->ss_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_SUPER);
-	}
 
 	/* Preallocate control endpoint request. */
 	uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
@@ -741,9 +730,7 @@ error:
 		kfree(uvc->control_buf);
 	}
 
-	kfree(f->descriptors);
-	kfree(f->hs_descriptors);
-	kfree(f->ss_descriptors);
+	usb_free_all_descriptors(f);
 	return ret;
 }
 
diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index e156e3f..35bcc83 100644
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -983,8 +983,10 @@ static int __init printer_func_bind(struct usb_configuration *c,
 {
 	struct printer_dev *dev = container_of(f, struct printer_dev, function);
 	struct usb_composite_dev *cdev = c->cdev;
-	struct usb_ep		*in_ep, *out_ep;
+	struct usb_ep *in_ep;
+	struct usb_ep *out_ep = NULL;
 	int id;
+	int ret;
 
 	id = usb_interface_id(c, f);
 	if (id < 0)
@@ -1010,6 +1012,11 @@ autoconf_fail:
 	hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
 	hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
 
+	ret = usb_assign_descriptors(f, fs_printer_function,
+			hs_printer_function, NULL);
+	if (ret)
+		return ret;
+
 	dev->in_ep = in_ep;
 	dev->out_ep = out_ep;
 	return 0;
@@ -1018,6 +1025,7 @@ autoconf_fail:
 static void printer_func_unbind(struct usb_configuration *c,
 		struct usb_function *f)
 {
+	usb_free_all_descriptors(f);
 }
 
 static int printer_func_set_alt(struct usb_function *f,
@@ -1110,8 +1118,6 @@ static int __init printer_bind_config(struct usb_configuration *c)
 	dev = &usb_printer_gadget;
 
 	dev->function.name = shortname;
-	dev->function.descriptors = fs_printer_function;
-	dev->function.hs_descriptors = hs_printer_function;
 	dev->function.bind = printer_func_bind;
 	dev->function.setup = printer_func_setup;
 	dev->function.unbind = printer_func_unbind;
diff --git a/drivers/usb/gadget/tcm_usb_gadget.c b/drivers/usb/gadget/tcm_usb_gadget.c
index 4959609..27a2337 100644
--- a/drivers/usb/gadget/tcm_usb_gadget.c
+++ b/drivers/usb/gadget/tcm_usb_gadget.c
@@ -2240,6 +2240,7 @@ static int usbg_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_gadget	*gadget = c->cdev->gadget;
 	struct usb_ep		*ep;
 	int			iface;
+	int			ret;
 
 	iface = usb_interface_id(c, f);
 	if (iface < 0)
@@ -2290,6 +2291,11 @@ static int usbg_bind(struct usb_configuration *c, struct usb_function *f)
 		uasp_ss_status_desc.bEndpointAddress;
 	uasp_fs_cmd_desc.bEndpointAddress = uasp_ss_cmd_desc.bEndpointAddress;
 
+	ret = usb_assign_descriptors(f, uasp_fs_function_desc,
+			uasp_hs_function_desc, uasp_ss_function_desc);
+	if (ret)
+		goto ep_fail;
+
 	return 0;
 ep_fail:
 	pr_err("Can't claim all required eps\n");
@@ -2305,6 +2311,7 @@ static void usbg_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct f_uas *fu = to_f_uas(f);
 
+	usb_free_all_descriptors(f);
 	kfree(fu);
 }
 
@@ -2385,9 +2392,6 @@ static int usbg_cfg_bind(struct usb_configuration *c)
 	if (!fu)
 		return -ENOMEM;
 	fu->function.name = "Target Function";
-	fu->function.descriptors = uasp_fs_function_desc;
-	fu->function.hs_descriptors = uasp_hs_function_desc;
-	fu->function.ss_descriptors = uasp_ss_function_desc;
 	fu->function.bind = usbg_bind;
 	fu->function.unbind = usbg_unbind;
 	fu->function.set_alt = usbg_set_alt;
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 8634a12..b09c37e 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -119,7 +119,7 @@ struct usb_configuration;
 struct usb_function {
 	const char			*name;
 	struct usb_gadget_strings	**strings;
-	struct usb_descriptor_header	**descriptors;
+	struct usb_descriptor_header	**fs_descriptors;
 	struct usb_descriptor_header	**hs_descriptors;
 	struct usb_descriptor_header	**ss_descriptors;
 
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 5b6e508..0af6569 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -939,6 +939,13 @@ static inline void usb_free_descriptors(struct usb_descriptor_header **v)
 	kfree(v);
 }
 
+struct usb_function;
+int usb_assign_descriptors(struct usb_function *f,
+		struct usb_descriptor_header **fs,
+		struct usb_descriptor_header **hs,
+		struct usb_descriptor_header **ss);
+void usb_free_all_descriptors(struct usb_function *f);
+
 /*-------------------------------------------------------------------------*/
 
 /* utility to simplify map/unmap of usb_requests to/from DMA */