2 * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
14 /* #define VERBOSE_DEBUG */
16 #include <linux/kernel.h>
17 #include <linux/gfp.h>
18 #include <linux/device.h>
19 #include <linux/ctype.h>
20 #include <linux/etherdevice.h>
21 #include <linux/ethtool.h>
27 * This component encapsulates the Ethernet link glue needed to provide
28 * one (!) network link through the USB gadget stack, normally "usb0".
30 * The control and data models are handled by the function driver which
31 * connects to this code; such as CDC Ethernet (ECM or EEM),
32 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
35 * Link level addressing is handled by this component using module
36 * parameters; if no such parameters are provided, random link level
37 * addresses are used. Each end of the link uses one address. The
38 * host end address is exported in various ways, and is often recorded
39 * in configuration databases.
41 * The driver which assembles each configuration using such a link is
42 * responsible for ensuring that each configuration includes at most one
43 * instance of is network link. (The network layer provides ways for
44 * this single "physical" link to be used by multiple virtual links.)
47 #define UETH__VERSION "29-May-2008"
50 /* lock is held while accessing port_usb
51 * or updating its backlink port_usb->ioport
54 struct gether *port_usb;
56 struct net_device *net;
57 struct usb_gadget *gadget;
59 spinlock_t req_lock; /* guard {rx,tx}_reqs */
60 struct list_head tx_reqs, rx_reqs;
63 struct sk_buff_head rx_frames;
66 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
67 int (*unwrap)(struct gether *,
69 struct sk_buff_head *list);
71 struct work_struct work;
74 #define WORK_RX_MEMORY 0
77 u8 host_mac[ETH_ALEN];
80 /*-------------------------------------------------------------------------*/
82 #define RX_EXTRA 20 /* bytes guarding against rx overflows */
84 #define DEFAULT_QLEN 2 /* double buffering by default */
87 #ifdef CONFIG_USB_GADGET_DUALSPEED
89 static unsigned qmult = 5;
90 module_param(qmult, uint, S_IRUGO|S_IWUSR);
91 MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");
93 #else /* full speed (low speed doesn't do bulk) */
97 /* for dual-speed hardware, use deeper queues at high/super speed */
98 static inline int qlen(struct usb_gadget *gadget)
100 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
101 gadget->speed == USB_SPEED_SUPER))
102 return qmult * DEFAULT_QLEN;
107 /*-------------------------------------------------------------------------*/
109 /* REVISIT there must be a better way than having two sets
118 #define xprintk(d, level, fmt, args...) \
119 printk(level "%s: " fmt , (d)->net->name , ## args)
123 #define DBG(dev, fmt, args...) \
124 xprintk(dev , KERN_DEBUG , fmt , ## args)
126 #define DBG(dev, fmt, args...) \
133 #define VDBG(dev, fmt, args...) \
137 #define ERROR(dev, fmt, args...) \
138 xprintk(dev , KERN_ERR , fmt , ## args)
139 #define INFO(dev, fmt, args...) \
140 xprintk(dev , KERN_INFO , fmt , ## args)
142 /*-------------------------------------------------------------------------*/
144 /* NETWORK DRIVER HOOKUP (to the layer above this driver) */
146 static int ueth_change_mtu(struct net_device *net, int new_mtu)
148 struct eth_dev *dev = netdev_priv(net);
152 /* don't change MTU on "live" link (peer won't know) */
153 spin_lock_irqsave(&dev->lock, flags);
156 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
160 spin_unlock_irqrestore(&dev->lock, flags);
165 static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
167 struct eth_dev *dev = netdev_priv(net);
169 strlcpy(p->driver, "g_ether", sizeof p->driver);
170 strlcpy(p->version, UETH__VERSION, sizeof p->version);
171 strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
172 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info);
175 /* REVISIT can also support:
176 * - WOL (by tracking suspends and issuing remote wakeup)
177 * - msglevel (implies updated messaging)
178 * - ... probably more ethtool ops
181 static const struct ethtool_ops ops = {
182 .get_drvinfo = eth_get_drvinfo,
183 .get_link = ethtool_op_get_link,
186 static void defer_kevent(struct eth_dev *dev, int flag)
188 if (test_and_set_bit(flag, &dev->todo))
190 if (!schedule_work(&dev->work))
191 ERROR(dev, "kevent %d may have been dropped\n", flag);
193 DBG(dev, "kevent %d scheduled\n", flag);
196 static void rx_complete(struct usb_ep *ep, struct usb_request *req);
199 rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
202 int retval = -ENOMEM;
207 spin_lock_irqsave(&dev->lock, flags);
209 out = dev->port_usb->out_ep;
212 spin_unlock_irqrestore(&dev->lock, flags);
218 /* Padding up to RX_EXTRA handles minor disagreements with host.
219 * Normally we use the USB "terminate on short read" convention;
220 * so allow up to (N*maxpacket), since that memory is normally
221 * already allocated. Some hardware doesn't deal well with short
222 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
223 * byte off the end (to force hardware errors on overflow).
225 * RNDIS uses internal framing, and explicitly allows senders to
226 * pad to end-of-packet. That's potentially nice for speed, but
227 * means receivers can't recover lost synch on their own (because
228 * new packets don't only start after a short RX).
230 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
231 size += dev->port_usb->header_len;
232 size += out->maxpacket - 1;
233 size -= size % out->maxpacket;
235 if (dev->port_usb->is_fixed)
236 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
238 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
240 DBG(dev, "no rx skb\n");
244 /* Some platforms perform better when IP packets are aligned,
245 * but on at least one, checksumming fails otherwise. Note:
246 * RNDIS headers involve variable numbers of LE32 values.
248 skb_reserve(skb, NET_IP_ALIGN);
250 req->buf = skb->data;
252 req->complete = rx_complete;
255 retval = usb_ep_queue(out, req, gfp_flags);
256 if (retval == -ENOMEM)
258 defer_kevent(dev, WORK_RX_MEMORY);
260 DBG(dev, "rx submit --> %d\n", retval);
262 dev_kfree_skb_any(skb);
263 spin_lock_irqsave(&dev->req_lock, flags);
264 list_add(&req->list, &dev->rx_reqs);
265 spin_unlock_irqrestore(&dev->req_lock, flags);
270 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
272 struct sk_buff *skb = req->context, *skb2;
273 struct eth_dev *dev = ep->driver_data;
274 int status = req->status;
278 /* normal completion */
280 skb_put(skb, req->actual);
285 spin_lock_irqsave(&dev->lock, flags);
287 status = dev->unwrap(dev->port_usb,
291 dev_kfree_skb_any(skb);
294 spin_unlock_irqrestore(&dev->lock, flags);
296 skb_queue_tail(&dev->rx_frames, skb);
300 skb2 = skb_dequeue(&dev->rx_frames);
303 || ETH_HLEN > skb2->len
304 || skb2->len > ETH_FRAME_LEN) {
305 dev->net->stats.rx_errors++;
306 dev->net->stats.rx_length_errors++;
307 DBG(dev, "rx length %d\n", skb2->len);
308 dev_kfree_skb_any(skb2);
311 skb2->protocol = eth_type_trans(skb2, dev->net);
312 dev->net->stats.rx_packets++;
313 dev->net->stats.rx_bytes += skb2->len;
315 /* no buffer copies needed, unless hardware can't
318 status = netif_rx(skb2);
320 skb2 = skb_dequeue(&dev->rx_frames);
324 /* software-driven interface shutdown */
325 case -ECONNRESET: /* unlink */
326 case -ESHUTDOWN: /* disconnect etc */
327 VDBG(dev, "rx shutdown, code %d\n", status);
330 /* for hardware automagic (such as pxa) */
331 case -ECONNABORTED: /* endpoint reset */
332 DBG(dev, "rx %s reset\n", ep->name);
333 defer_kevent(dev, WORK_RX_MEMORY);
335 dev_kfree_skb_any(skb);
340 dev->net->stats.rx_over_errors++;
344 dev->net->stats.rx_errors++;
345 DBG(dev, "rx status %d\n", status);
350 dev_kfree_skb_any(skb);
351 if (!netif_running(dev->net)) {
353 spin_lock(&dev->req_lock);
354 list_add(&req->list, &dev->rx_reqs);
355 spin_unlock(&dev->req_lock);
359 rx_submit(dev, req, GFP_ATOMIC);
362 static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
365 struct usb_request *req;
370 /* queue/recycle up to N requests */
372 list_for_each_entry(req, list, list) {
377 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
379 return list_empty(list) ? -ENOMEM : 0;
380 list_add(&req->list, list);
387 struct list_head *next;
389 next = req->list.next;
390 list_del(&req->list);
391 usb_ep_free_request(ep, req);
396 req = container_of(next, struct usb_request, list);
401 static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
405 spin_lock(&dev->req_lock);
406 status = prealloc(&dev->tx_reqs, link->in_ep, n);
409 status = prealloc(&dev->rx_reqs, link->out_ep, n);
414 DBG(dev, "can't alloc requests\n");
416 spin_unlock(&dev->req_lock);
420 static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
422 struct usb_request *req;
425 /* fill unused rxq slots with some skb */
426 spin_lock_irqsave(&dev->req_lock, flags);
427 while (!list_empty(&dev->rx_reqs)) {
428 req = container_of(dev->rx_reqs.next,
429 struct usb_request, list);
430 list_del_init(&req->list);
431 spin_unlock_irqrestore(&dev->req_lock, flags);
433 if (rx_submit(dev, req, gfp_flags) < 0) {
434 defer_kevent(dev, WORK_RX_MEMORY);
438 spin_lock_irqsave(&dev->req_lock, flags);
440 spin_unlock_irqrestore(&dev->req_lock, flags);
443 static void eth_work(struct work_struct *work)
445 struct eth_dev *dev = container_of(work, struct eth_dev, work);
447 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
448 if (netif_running(dev->net))
449 rx_fill(dev, GFP_KERNEL);
453 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
456 static void tx_complete(struct usb_ep *ep, struct usb_request *req)
458 struct sk_buff *skb = req->context;
459 struct eth_dev *dev = ep->driver_data;
461 switch (req->status) {
463 dev->net->stats.tx_errors++;
464 VDBG(dev, "tx err %d\n", req->status);
466 case -ECONNRESET: /* unlink */
467 case -ESHUTDOWN: /* disconnect etc */
470 dev->net->stats.tx_bytes += skb->len;
472 dev->net->stats.tx_packets++;
474 spin_lock(&dev->req_lock);
475 list_add(&req->list, &dev->tx_reqs);
476 spin_unlock(&dev->req_lock);
477 dev_kfree_skb_any(skb);
479 atomic_dec(&dev->tx_qlen);
480 if (netif_carrier_ok(dev->net))
481 netif_wake_queue(dev->net);
484 static inline int is_promisc(u16 cdc_filter)
486 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
489 static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
490 struct net_device *net)
492 struct eth_dev *dev = netdev_priv(net);
493 int length = skb->len;
495 struct usb_request *req = NULL;
500 spin_lock_irqsave(&dev->lock, flags);
502 in = dev->port_usb->in_ep;
503 cdc_filter = dev->port_usb->cdc_filter;
508 spin_unlock_irqrestore(&dev->lock, flags);
511 dev_kfree_skb_any(skb);
515 /* apply outgoing CDC or RNDIS filters */
516 if (!is_promisc(cdc_filter)) {
517 u8 *dest = skb->data;
519 if (is_multicast_ether_addr(dest)) {
522 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
523 * SET_ETHERNET_MULTICAST_FILTERS requests
525 if (is_broadcast_ether_addr(dest))
526 type = USB_CDC_PACKET_TYPE_BROADCAST;
528 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
529 if (!(cdc_filter & type)) {
530 dev_kfree_skb_any(skb);
534 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
537 spin_lock_irqsave(&dev->req_lock, flags);
539 * this freelist can be empty if an interrupt triggered disconnect()
540 * and reconfigured the gadget (shutting down this queue) after the
541 * network stack decided to xmit but before we got the spinlock.
543 if (list_empty(&dev->tx_reqs)) {
544 spin_unlock_irqrestore(&dev->req_lock, flags);
545 return NETDEV_TX_BUSY;
548 req = container_of(dev->tx_reqs.next, struct usb_request, list);
549 list_del(&req->list);
551 /* temporarily stop TX queue when the freelist empties */
552 if (list_empty(&dev->tx_reqs))
553 netif_stop_queue(net);
554 spin_unlock_irqrestore(&dev->req_lock, flags);
556 /* no buffer copies needed, unless the network stack did it
557 * or the hardware can't use skb buffers.
558 * or there's not enough space for extra headers we need
563 spin_lock_irqsave(&dev->lock, flags);
565 skb = dev->wrap(dev->port_usb, skb);
566 spin_unlock_irqrestore(&dev->lock, flags);
572 req->buf = skb->data;
574 req->complete = tx_complete;
576 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
577 if (dev->port_usb->is_fixed &&
578 length == dev->port_usb->fixed_in_len &&
579 (length % in->maxpacket) == 0)
584 /* use zlp framing on tx for strict CDC-Ether conformance,
585 * though any robust network rx path ignores extra padding.
586 * and some hardware doesn't like to write zlps.
588 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
591 req->length = length;
593 retval = usb_ep_queue(in, req, GFP_ATOMIC);
596 DBG(dev, "tx queue err %d\n", retval);
599 net->trans_start = jiffies;
600 atomic_inc(&dev->tx_qlen);
604 dev_kfree_skb_any(skb);
606 dev->net->stats.tx_dropped++;
607 spin_lock_irqsave(&dev->req_lock, flags);
608 if (list_empty(&dev->tx_reqs))
609 netif_start_queue(net);
610 list_add(&req->list, &dev->tx_reqs);
611 spin_unlock_irqrestore(&dev->req_lock, flags);
616 /*-------------------------------------------------------------------------*/
618 static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
620 DBG(dev, "%s\n", __func__);
622 /* fill the rx queue */
623 rx_fill(dev, gfp_flags);
625 /* and open the tx floodgates */
626 atomic_set(&dev->tx_qlen, 0);
627 netif_wake_queue(dev->net);
630 static int eth_open(struct net_device *net)
632 struct eth_dev *dev = netdev_priv(net);
635 DBG(dev, "%s\n", __func__);
636 if (netif_carrier_ok(dev->net))
637 eth_start(dev, GFP_KERNEL);
639 spin_lock_irq(&dev->lock);
640 link = dev->port_usb;
641 if (link && link->open)
643 spin_unlock_irq(&dev->lock);
648 static int eth_stop(struct net_device *net)
650 struct eth_dev *dev = netdev_priv(net);
653 VDBG(dev, "%s\n", __func__);
654 netif_stop_queue(net);
656 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
657 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
658 dev->net->stats.rx_errors, dev->net->stats.tx_errors
661 /* ensure there are no more active requests */
662 spin_lock_irqsave(&dev->lock, flags);
664 struct gether *link = dev->port_usb;
665 const struct usb_endpoint_descriptor *in;
666 const struct usb_endpoint_descriptor *out;
671 /* NOTE: we have no abort-queue primitive we could use
672 * to cancel all pending I/O. Instead, we disable then
673 * reenable the endpoints ... this idiom may leave toggle
674 * wrong, but that's a self-correcting error.
676 * REVISIT: we *COULD* just let the transfers complete at
677 * their own pace; the network stack can handle old packets.
678 * For the moment we leave this here, since it works.
680 in = link->in_ep->desc;
681 out = link->out_ep->desc;
682 usb_ep_disable(link->in_ep);
683 usb_ep_disable(link->out_ep);
684 if (netif_carrier_ok(net)) {
685 DBG(dev, "host still using in/out endpoints\n");
686 link->in_ep->desc = in;
687 link->out_ep->desc = out;
688 usb_ep_enable(link->in_ep);
689 usb_ep_enable(link->out_ep);
692 spin_unlock_irqrestore(&dev->lock, flags);
697 /*-------------------------------------------------------------------------*/
699 /* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
700 static char *dev_addr;
701 module_param(dev_addr, charp, S_IRUGO);
702 MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
704 /* this address is invisible to ifconfig */
705 static char *host_addr;
706 module_param(host_addr, charp, S_IRUGO);
707 MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
709 static int get_ether_addr(const char *str, u8 *dev_addr)
714 for (i = 0; i < 6; i++) {
717 if ((*str == '.') || (*str == ':'))
719 num = hex_to_bin(*str++) << 4;
720 num |= hex_to_bin(*str++);
723 if (is_valid_ether_addr(dev_addr))
726 random_ether_addr(dev_addr);
730 static struct eth_dev *the_dev;
732 static const struct net_device_ops eth_netdev_ops = {
733 .ndo_open = eth_open,
734 .ndo_stop = eth_stop,
735 .ndo_start_xmit = eth_start_xmit,
736 .ndo_change_mtu = ueth_change_mtu,
737 .ndo_set_mac_address = eth_mac_addr,
738 .ndo_validate_addr = eth_validate_addr,
741 static struct device_type gadget_type = {
746 * gether_setup - initialize one ethernet-over-usb link
747 * @g: gadget to associated with these links
748 * @ethaddr: NULL, or a buffer in which the ethernet address of the
749 * host side of the link is recorded
752 * This sets up the single network link that may be exported by a
753 * gadget driver using this framework. The link layer addresses are
754 * set up using module parameters.
756 * Returns negative errno, or zero on success
758 int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
761 struct net_device *net;
767 net = alloc_etherdev(sizeof *dev);
771 dev = netdev_priv(net);
772 spin_lock_init(&dev->lock);
773 spin_lock_init(&dev->req_lock);
774 INIT_WORK(&dev->work, eth_work);
775 INIT_LIST_HEAD(&dev->tx_reqs);
776 INIT_LIST_HEAD(&dev->rx_reqs);
778 skb_queue_head_init(&dev->rx_frames);
780 /* network device setup */
782 strcpy(net->name, "usb%d");
784 if (get_ether_addr(dev_addr, net->dev_addr))
786 "using random %s ethernet address\n", "self");
787 if (get_ether_addr(host_addr, dev->host_mac))
789 "using random %s ethernet address\n", "host");
792 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
794 net->netdev_ops = ð_netdev_ops;
796 SET_ETHTOOL_OPS(net, &ops);
799 SET_NETDEV_DEV(net, &g->dev);
800 SET_NETDEV_DEVTYPE(net, &gadget_type);
802 status = register_netdev(net);
804 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
807 INFO(dev, "MAC %pM\n", net->dev_addr);
808 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
812 /* two kinds of host-initiated state changes:
813 * - iff DATA transfer is active, carrier is "on"
814 * - tx queueing enabled if open *and* carrier is "on"
816 netif_carrier_off(net);
823 * gether_cleanup - remove Ethernet-over-USB device
826 * This is called to free all resources allocated by @gether_setup().
828 void gether_cleanup(void)
833 unregister_netdev(the_dev->net);
834 flush_work_sync(&the_dev->work);
835 free_netdev(the_dev->net);
842 * gether_connect - notify network layer that USB link is active
843 * @link: the USB link, set up with endpoints, descriptors matching
844 * current device speed, and any framing wrapper(s) set up.
845 * Context: irqs blocked
847 * This is called to activate endpoints and let the network layer know
848 * the connection is active ("carrier detect"). It may cause the I/O
849 * queues to open and start letting network packets flow, but will in
850 * any case activate the endpoints so that they respond properly to the
853 * Verify net_device pointer returned using IS_ERR(). If it doesn't
854 * indicate some error code (negative errno), ep->driver_data values
855 * have been overwritten.
857 struct net_device *gether_connect(struct gether *link)
859 struct eth_dev *dev = the_dev;
863 return ERR_PTR(-EINVAL);
865 link->in_ep->driver_data = dev;
866 result = usb_ep_enable(link->in_ep);
868 DBG(dev, "enable %s --> %d\n",
869 link->in_ep->name, result);
873 link->out_ep->driver_data = dev;
874 result = usb_ep_enable(link->out_ep);
876 DBG(dev, "enable %s --> %d\n",
877 link->out_ep->name, result);
882 result = alloc_requests(dev, link, qlen(dev->gadget));
885 dev->zlp = link->is_zlp_ok;
886 DBG(dev, "qlen %d\n", qlen(dev->gadget));
888 dev->header_len = link->header_len;
889 dev->unwrap = link->unwrap;
890 dev->wrap = link->wrap;
892 spin_lock(&dev->lock);
893 dev->port_usb = link;
895 if (netif_running(dev->net)) {
902 spin_unlock(&dev->lock);
904 netif_carrier_on(dev->net);
905 if (netif_running(dev->net))
906 eth_start(dev, GFP_ATOMIC);
908 /* on error, disable any endpoints */
910 (void) usb_ep_disable(link->out_ep);
912 (void) usb_ep_disable(link->in_ep);
915 /* caller is responsible for cleanup on error */
917 return ERR_PTR(result);
922 * gether_disconnect - notify network layer that USB link is inactive
923 * @link: the USB link, on which gether_connect() was called
924 * Context: irqs blocked
926 * This is called to deactivate endpoints and let the network layer know
927 * the connection went inactive ("no carrier").
929 * On return, the state is as if gether_connect() had never been called.
930 * The endpoints are inactive, and accordingly without active USB I/O.
931 * Pointers to endpoint descriptors and endpoint private data are nulled.
933 void gether_disconnect(struct gether *link)
935 struct eth_dev *dev = link->ioport;
936 struct usb_request *req;
942 DBG(dev, "%s\n", __func__);
944 netif_stop_queue(dev->net);
945 netif_carrier_off(dev->net);
947 /* disable endpoints, forcing (synchronous) completion
948 * of all pending i/o. then free the request objects
949 * and forget about the endpoints.
951 usb_ep_disable(link->in_ep);
952 spin_lock(&dev->req_lock);
953 while (!list_empty(&dev->tx_reqs)) {
954 req = container_of(dev->tx_reqs.next,
955 struct usb_request, list);
956 list_del(&req->list);
958 spin_unlock(&dev->req_lock);
959 usb_ep_free_request(link->in_ep, req);
960 spin_lock(&dev->req_lock);
962 spin_unlock(&dev->req_lock);
963 link->in_ep->driver_data = NULL;
964 link->in_ep->desc = NULL;
966 usb_ep_disable(link->out_ep);
967 spin_lock(&dev->req_lock);
968 while (!list_empty(&dev->rx_reqs)) {
969 req = container_of(dev->rx_reqs.next,
970 struct usb_request, list);
971 list_del(&req->list);
973 spin_unlock(&dev->req_lock);
974 usb_ep_free_request(link->out_ep, req);
975 spin_lock(&dev->req_lock);
977 spin_unlock(&dev->req_lock);
978 link->out_ep->driver_data = NULL;
979 link->out_ep->desc = NULL;
981 /* finish forgetting about this USB link episode */
986 spin_lock(&dev->lock);
987 dev->port_usb = NULL;
989 spin_unlock(&dev->lock);