[linux-2.6-block.git] / drivers / staging / usbip / stub_tx.c

/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#include "usbip_common.h"
#include "stub.h"


static void stub_free_priv_and_urb(struct stub_priv *priv)
{
	struct urb *urb = priv->urb;

	kfree(urb->setup_packet);
	kfree(urb->transfer_buffer);
	list_del(&priv->list);
	kmem_cache_free(stub_priv_cache, priv);
	usb_free_urb(urb);
}

/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
			     __u32 status)
{
	struct stub_unlink *unlink;

	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
	if (!unlink) {
		dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
		usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
		return;
	}

	unlink->seqnum = seqnum;
	unlink->status = status;

	list_add_tail(&unlink->list, &sdev->unlink_tx);
}

/**
 * stub_complete - completion handler of a usbip urb
 * @urb: pointer to the urb completed
 *
 * When a urb has completed, the USB core driver calls this function mostly in
 * the interrupt context. To return the result of a urb, the completed urb is
 * linked to the pending list of returning.
 *
 */
void stub_complete(struct urb *urb)
{
	struct stub_priv *priv = (struct stub_priv *) urb->context;
	struct stub_device *sdev = priv->sdev;
	unsigned long flags;

	usbip_dbg_stub_tx("complete! status %d\n", urb->status);


	switch (urb->status) {
	case 0:
		/* OK */
		break;
	case -ENOENT:
		usbip_uinfo("stopped by a call of usb_kill_urb() because of"
					"cleaning up a virtual connection\n");
		return;
	case -ECONNRESET:
		usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
		break;
	case -EPIPE:
		usbip_uinfo("endpoint %d is stalled\n",
						usb_pipeendpoint(urb->pipe));
		break;
	case -ESHUTDOWN:
		usbip_uinfo("device removed?\n");
		break;
	default:
		usbip_uinfo("urb completion with non-zero status %d\n",
							urb->status);
	}

	/* link a urb to the queue of tx. */
	spin_lock_irqsave(&sdev->priv_lock, flags);

	if (priv->unlinking) {
		stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
		stub_free_priv_and_urb(priv);
	} else
		list_move_tail(&priv->list, &sdev->priv_tx);


	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	/* wake up tx_thread */
	wake_up(&sdev->tx_waitq);
}


/*-------------------------------------------------------------------------*/
/* fill PDU */

static inline void setup_base_pdu(struct usbip_header_basic *base,
		__u32 command, __u32 seqnum)
{
	base->command = command;
	base->seqnum  = seqnum;
	base->devid   = 0;
	base->ep      = 0;
	base->direction   = 0;
}

static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
{
	struct stub_priv *priv = (struct stub_priv *) urb->context;

	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);

	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
}

static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
		struct stub_unlink *unlink)
{
	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);

	rpdu->u.ret_unlink.status = unlink->status;
}


/*-------------------------------------------------------------------------*/
/* send RET_SUBMIT */

static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
{
	unsigned long flags;
	struct stub_priv *priv, *tmp;

	spin_lock_irqsave(&sdev->priv_lock, flags);

	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
		list_move_tail(&priv->list, &sdev->priv_free);
		spin_unlock_irqrestore(&sdev->priv_lock, flags);
		return priv;
	}

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return NULL;
}

static int stub_send_ret_submit(struct stub_device *sdev)
{
	unsigned long flags;
	struct stub_priv *priv, *tmp;

	struct msghdr msg;
	struct kvec iov[3];
	size_t txsize;

	size_t total_size = 0;

	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
		int ret;
		struct urb *urb = priv->urb;
		struct usbip_header pdu_header;
		void *iso_buffer = NULL;

		txsize = 0;
		memset(&pdu_header, 0, sizeof(pdu_header));
		memset(&msg, 0, sizeof(msg));
		memset(&iov, 0, sizeof(iov));

		usbip_dbg_stub_tx("setup txdata urb %p\n", urb);


		/* 1. setup usbip_header */
		setup_ret_submit_pdu(&pdu_header, urb);
		usbip_header_correct_endian(&pdu_header, 1);

		iov[0].iov_base = &pdu_header;
		iov[0].iov_len  = sizeof(pdu_header);
		txsize += sizeof(pdu_header);

		/* 2. setup transfer buffer */
		if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
			iov[1].iov_base = urb->transfer_buffer;
			iov[1].iov_len  = urb->actual_length;
			txsize += urb->actual_length;
		}

		/* 3. setup iso_packet_descriptor */
		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
			ssize_t len = 0;

			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
			if (!iso_buffer) {
				usbip_event_add(&sdev->ud,
						SDEV_EVENT_ERROR_MALLOC);
				return -1;
			}

			iov[2].iov_base = iso_buffer;
			iov[2].iov_len  = len;
			txsize += len;
		}

		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
				     3, txsize);
		if (ret != txsize) {
			dev_err(&sdev->interface->dev,
				"sendmsg failed!, retval %d for %zd\n",
				ret, txsize);
			kfree(iso_buffer);
			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
			return -1;
		}

		kfree(iso_buffer);
		usbip_dbg_stub_tx("send txdata\n");

		total_size += txsize;
	}


	spin_lock_irqsave(&sdev->priv_lock, flags);

	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
		stub_free_priv_and_urb(priv);
	}

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return total_size;
}


/*-------------------------------------------------------------------------*/
/* send RET_UNLINK */

static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
{
	unsigned long flags;
	struct stub_unlink *unlink, *tmp;

	spin_lock_irqsave(&sdev->priv_lock, flags);

	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
		list_move_tail(&unlink->list, &sdev->unlink_free);
		spin_unlock_irqrestore(&sdev->priv_lock, flags);
		return unlink;
	}

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return NULL;
}


static int stub_send_ret_unlink(struct stub_device *sdev)
{
	unsigned long flags;
	struct stub_unlink *unlink, *tmp;

	struct msghdr msg;
	struct kvec iov[1];
	size_t txsize;

	size_t total_size = 0;

	while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
		int ret;
		struct usbip_header pdu_header;

		txsize = 0;
		memset(&pdu_header, 0, sizeof(pdu_header));
		memset(&msg, 0, sizeof(msg));
		memset(&iov, 0, sizeof(iov));

		usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);

		/* 1. setup usbip_header */
		setup_ret_unlink_pdu(&pdu_header, unlink);
		usbip_header_correct_endian(&pdu_header, 1);

		iov[0].iov_base = &pdu_header;
		iov[0].iov_len  = sizeof(pdu_header);
		txsize += sizeof(pdu_header);

		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
				     1, txsize);
		if (ret != txsize) {
			dev_err(&sdev->interface->dev,
				"sendmsg failed!, retval %d for %zd\n",
				ret, txsize);
			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
			return -1;
		}


		usbip_dbg_stub_tx("send txdata\n");

		total_size += txsize;
	}


	spin_lock_irqsave(&sdev->priv_lock, flags);

	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
		list_del(&unlink->list);
		kfree(unlink);
	}

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return total_size;
}


/*-------------------------------------------------------------------------*/

void stub_tx_loop(struct usbip_task *ut)
{
	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
	struct stub_device *sdev = container_of(ud, struct stub_device, ud);

	while (1) {
		if (signal_pending(current)) {
			usbip_dbg_stub_tx("signal catched\n");
			break;
		}

		if (usbip_event_happened(ud))
			break;

		/*
		 * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
		 * looks at only priv_init queue. If the completion of a URB is
		 * earlier than the receive of CMD_UNLINK, priv is moved to
		 * priv_tx queue and stub_rx does not find the target priv. In
		 * this case, vhci_rx receives the result of the submit request
		 * and then receives the result of the unlink request. The
		 * result of the submit is given back to the usbcore as the
		 * completion of the unlink request. The request of the
		 * unlink is ignored. This is ok because a driver who calls
		 * usb_unlink_urb() understands the unlink was too late by
		 * getting the status of the given-backed URB which has the
		 * status of usb_submit_urb().
		 */
		if (stub_send_ret_submit(sdev) < 0)
			break;

		if (stub_send_ret_unlink(sdev) < 0)
			break;

		wait_event_interruptible(sdev->tx_waitq,
				(!list_empty(&sdev->priv_tx) ||
				 !list_empty(&sdev->unlink_tx)));
	}
}
Commit	Line	Data
4d7b5c7f TH	1	/*
	2	* Copyright (C) 2003-2008 Takahiro Hirofuchi
	3	*
	4	* This is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
	17	* USA.
	18	*/
	19
	20	#include "usbip_common.h"
	21	#include "stub.h"
	22
	23
	24	static void stub_free_priv_and_urb(struct stub_priv *priv)
	25	{
	26	struct urb *urb = priv->urb;
	27
	28	kfree(urb->setup_packet);
	29	kfree(urb->transfer_buffer);
	30	list_del(&priv->list);
	31	kmem_cache_free(stub_priv_cache, priv);
	32	usb_free_urb(urb);
	33	}
	34
	35	/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
	36	void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
	37	__u32 status)
	38	{
	39	struct stub_unlink *unlink;
	40
	41	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
	42	if (!unlink) {
	43	dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
	44	usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
	45	return;
	46	}
	47
	48	unlink->seqnum = seqnum;
	49	unlink->status = status;
	50
	51	list_add_tail(&unlink->list, &sdev->unlink_tx);
	52	}
	53
	54	/**
	55	* stub_complete - completion handler of a usbip urb
	56	* @urb: pointer to the urb completed
4d7b5c7f TH	57	*
	58	* When a urb has completed, the USB core driver calls this function mostly in
	59	* the interrupt context. To return the result of a urb, the completed urb is
	60	* linked to the pending list of returning.
	61	*
	62	*/
	63	void stub_complete(struct urb *urb)
	64	{
	65	struct stub_priv priv = (struct stub_priv ) urb->context;
	66	struct stub_device *sdev = priv->sdev;
	67	unsigned long flags;
	68
b8868e45	69	usbip_dbg_stub_tx("complete! status %d\n", urb->status);
4d7b5c7f TH	70
	71
	72	switch (urb->status) {
	73	case 0:
	74	/* OK */
	75	break;
	76	case -ENOENT:
b8868e45	77	usbip_uinfo("stopped by a call of usb_kill_urb() because of"
4d7b5c7f TH	78	"cleaning up a virtual connection\n");
	79	return;
	80	case -ECONNRESET:
b8868e45	81	usbip_uinfo("unlinked by a call of usb_unlink_urb()\n");
4d7b5c7f TH	82	break;
4d7b5c7f TH	83	case -EPIPE:
b8868e45 BM	84	usbip_uinfo("endpoint %d is stalled\n",
b8868e45 BM	85	usb_pipeendpoint(urb->pipe));
4d7b5c7f TH	86	break;
4d7b5c7f TH	87	case -ESHUTDOWN:
b8868e45	88	usbip_uinfo("device removed?\n");
4d7b5c7f TH	89	break;
4d7b5c7f TH	90	default:
b8868e45 BM	91	usbip_uinfo("urb completion with non-zero status %d\n",
b8868e45 BM	92	urb->status);
4d7b5c7f TH	93	}
	94
	95	/* link a urb to the queue of tx. */
	96	spin_lock_irqsave(&sdev->priv_lock, flags);
	97
	98	if (priv->unlinking) {
	99	stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
	100	stub_free_priv_and_urb(priv);
	101	} else
	102	list_move_tail(&priv->list, &sdev->priv_tx);
	103
	104
	105	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	106
	107	/* wake up tx_thread */
	108	wake_up(&sdev->tx_waitq);
	109	}
	110
	111
	112	/-------------------------------------------------------------------------/
	113	/* fill PDU */
	114
	115	static inline void setup_base_pdu(struct usbip_header_basic *base,
	116	__u32 command, __u32 seqnum)
	117	{
	118	base->command = command;
	119	base->seqnum = seqnum;
	120	base->devid = 0;
	121	base->ep = 0;
	122	base->direction = 0;
	123	}
	124
	125	static void setup_ret_submit_pdu(struct usbip_header rpdu, struct urb urb)
	126	{
	127	struct stub_priv priv = (struct stub_priv ) urb->context;
	128
	129	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
	130
	131	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
	132	}
	133
	134	static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
	135	struct stub_unlink *unlink)
	136	{
	137	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
	138
	139	rpdu->u.ret_unlink.status = unlink->status;
	140	}
	141
	142
	143	/-------------------------------------------------------------------------/
	144	/* send RET_SUBMIT */
	145
	146	static struct stub_priv dequeue_from_priv_tx(struct stub_device sdev)
	147	{
	148	unsigned long flags;
	149	struct stub_priv priv, tmp;
	150
	151	spin_lock_irqsave(&sdev->priv_lock, flags);
	152
	153	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
	154	list_move_tail(&priv->list, &sdev->priv_free);
	155	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	156	return priv;
157	}
158
159	spin_unlock_irqrestore(&sdev->priv_lock, flags);
160
161	return NULL;
162	}
163
164	static int stub_send_ret_submit(struct stub_device *sdev)
165	{
166	unsigned long flags;
167	struct stub_priv priv, tmp;
168
169	struct msghdr msg;
170	struct kvec iov[3];
171	size_t txsize;
172
173	size_t total_size = 0;
174
175	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
176	int ret;
177	struct urb *urb = priv->urb;
178	struct usbip_header pdu_header;
179	void *iso_buffer = NULL;
180
181	txsize = 0;
182	memset(&pdu_header, 0, sizeof(pdu_header));
183	memset(&msg, 0, sizeof(msg));
184	memset(&iov, 0, sizeof(iov));
185
b8868e45	186	usbip_dbg_stub_tx("setup txdata urb %p\n", urb);
4d7b5c7f TH	187
	188
	189	/* 1. setup usbip_header */
	190	setup_ret_submit_pdu(&pdu_header, urb);
	191	usbip_header_correct_endian(&pdu_header, 1);
	192
	193	iov[0].iov_base = &pdu_header;
	194	iov[0].iov_len = sizeof(pdu_header);
	195	txsize += sizeof(pdu_header);
	196
	197	/* 2. setup transfer buffer */
	198	if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
	199	iov[1].iov_base = urb->transfer_buffer;
	200	iov[1].iov_len = urb->actual_length;
	201	txsize += urb->actual_length;
	202	}
	203
	204	/* 3. setup iso_packet_descriptor */
	205	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
	206	ssize_t len = 0;
	207
	208	iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
	209	if (!iso_buffer) {
	210	usbip_event_add(&sdev->ud,
	211	SDEV_EVENT_ERROR_MALLOC);
	212	return -1;
	213	}
	214
	215	iov[2].iov_base = iso_buffer;
	216	iov[2].iov_len = len;
	217	txsize += len;
	218	}
	219
	220	ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
	221	3, txsize);
	222	if (ret != txsize) {
	223	dev_err(&sdev->interface->dev,
	224	"sendmsg failed!, retval %d for %zd\n",
	225	ret, txsize);
	226	kfree(iso_buffer);
	227	usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
	228	return -1;
	229	}
	230
	231	kfree(iso_buffer);
b8868e45	232	usbip_dbg_stub_tx("send txdata\n");
4d7b5c7f TH	233
	234	total_size += txsize;
	235	}
	236
	237
	238	spin_lock_irqsave(&sdev->priv_lock, flags);
	239
	240	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
	241	stub_free_priv_and_urb(priv);
	242	}
	243
	244	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	245
	246	return total_size;
	247	}
	248
	249
	250	/-------------------------------------------------------------------------/
	251	/* send RET_UNLINK */
	252
	253	static struct stub_unlink dequeue_from_unlink_tx(struct stub_device sdev)
	254	{
	255	unsigned long flags;
	256	struct stub_unlink unlink, tmp;
	257
	258	spin_lock_irqsave(&sdev->priv_lock, flags);
	259
	260	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
	261	list_move_tail(&unlink->list, &sdev->unlink_free);
	262	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	263	return unlink;
	264	}
	265
	266	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	267
	268	return NULL;
	269	}
	270
	271
	272	static int stub_send_ret_unlink(struct stub_device *sdev)
	273	{
	274	unsigned long flags;
	275	struct stub_unlink unlink, tmp;
	276
	277	struct msghdr msg;
	278	struct kvec iov[1];
	279	size_t txsize;
	280
	281	size_t total_size = 0;
	282
	283	while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
	284	int ret;
	285	struct usbip_header pdu_header;
	286
	287	txsize = 0;
	288	memset(&pdu_header, 0, sizeof(pdu_header));
	289	memset(&msg, 0, sizeof(msg));
	290	memset(&iov, 0, sizeof(iov));
	291
b8868e45	292	usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
4d7b5c7f TH	293
	294	/* 1. setup usbip_header */
	295	setup_ret_unlink_pdu(&pdu_header, unlink);
	296	usbip_header_correct_endian(&pdu_header, 1);
	297
	298	iov[0].iov_base = &pdu_header;
	299	iov[0].iov_len = sizeof(pdu_header);
	300	txsize += sizeof(pdu_header);
	301
	302	ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
	303	1, txsize);
	304	if (ret != txsize) {
	305	dev_err(&sdev->interface->dev,
	306	"sendmsg failed!, retval %d for %zd\n",
	307	ret, txsize);
	308	usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
	309	return -1;
	310	}
	311
	312
b8868e45	313	usbip_dbg_stub_tx("send txdata\n");
4d7b5c7f TH	314
	315	total_size += txsize;
	316	}
	317
	318
	319	spin_lock_irqsave(&sdev->priv_lock, flags);
	320
	321	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
	322	list_del(&unlink->list);
	323	kfree(unlink);
	324	}
	325
	326	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	327
	328	return total_size;
	329	}
	330
	331
	332	/-------------------------------------------------------------------------/
	333
	334	void stub_tx_loop(struct usbip_task *ut)
	335	{
	336	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
	337	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
	338
	339	while (1) {
	340	if (signal_pending(current)) {
b8868e45	341	usbip_dbg_stub_tx("signal catched\n");
4d7b5c7f TH	342	break;
	343	}
	344
b8868e45	345	if (usbip_event_happened(ud))
4d7b5c7f TH	346	break;
	347
	348	/*
	349	* send_ret_submit comes earlier than send_ret_unlink. stub_rx
	350	* looks at only priv_init queue. If the completion of a URB is
	351	* earlier than the receive of CMD_UNLINK, priv is moved to
	352	* priv_tx queue and stub_rx does not find the target priv. In
	353	* this case, vhci_rx receives the result of the submit request
	354	* and then receives the result of the unlink request. The
	355	* result of the submit is given back to the usbcore as the
	356	* completion of the unlink request. The request of the
	357	* unlink is ignored. This is ok because a driver who calls
	358	* usb_unlink_urb() understands the unlink was too late by
	359	* getting the status of the given-backed URB which has the
	360	* status of usb_submit_urb().
	361	*/
	362	if (stub_send_ret_submit(sdev) < 0)
	363	break;
	364
	365	if (stub_send_ret_unlink(sdev) < 0)
	366	break;
	367
	368	wait_event_interruptible(sdev->tx_waitq,
	369	(!list_empty(&sdev->priv_tx) \|\|
	370	!list_empty(&sdev->unlink_tx)));
	371	}
	372	}