source: rtems-libbsd/freebsd/sys/dev/usb/net/if_kue.c @ d145449

#include <machine/rtems-bsd-kernel-space.h>

/*-
 * Copyright (c) 1997, 1998, 1999, 2000
 *      Bill Paul <wpaul@ee.columbia.edu>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * Kawasaki LSI KL5KUSB101B USB to ethernet adapter driver.
 *
 * Written by Bill Paul <wpaul@ee.columbia.edu>
 * Electrical Engineering Department
 * Columbia University, New York City
 */

/*
 * The KLSI USB to ethernet adapter chip contains an USB serial interface,
 * ethernet MAC and embedded microcontroller (called the QT Engine).
 * The chip must have firmware loaded into it before it will operate.
 * Packets are passed between the chip and host via bulk transfers.
 * There is an interrupt endpoint mentioned in the software spec, however
 * it's currently unused. This device is 10Mbps half-duplex only, hence
 * there is no media selection logic. The MAC supports a 128 entry
 * multicast filter, though the exact size of the filter can depend
 * on the firmware. Curiously, while the software spec describes various
 * ethernet statistics counters, my sample adapter and firmware combination
 * claims not to support any statistics counters at all.
 *
 * Note that once we load the firmware in the device, we have to be
 * careful not to load it again: if you restart your computer but
 * leave the adapter attached to the USB controller, it may remain
 * powered on and retain its firmware. In this case, we don't need
 * to load the firmware a second time.
 *
 * Special thanks to Rob Furr for providing an ADS Technologies
 * adapter for development and testing. No monkeys were harmed during
 * the development of this driver.
 */

#include <sys/stdint.h>
#include <sys/stddef.h>
#include <rtems/bsd/sys/param.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <rtems/bsd/sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <rtems/bsd/sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

#include <net/if.h>
#include <net/if_var.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <rtems/bsd/local/usbdevs.h>

#define USB_DEBUG_VAR kue_debug
#include <dev/usb/usb_debug.h>
#include <dev/usb/usb_process.h>

#include <dev/usb/net/usb_ethernet.h>
#include <dev/usb/net/if_kuereg.h>
#include <dev/usb/net/if_kuefw.h>

/*
 * Various supported device vendors/products.
 */
static const STRUCT_USB_HOST_ID kue_devs[] = {
#define KUE_DEV(v,p) { USB_VP(USB_VENDOR_##v, USB_PRODUCT_##v##_##p) }
        KUE_DEV(3COM, 3C19250),
        KUE_DEV(3COM, 3C460),
        KUE_DEV(ABOCOM, URE450),
        KUE_DEV(ADS, UBS10BT),
        KUE_DEV(ADS, UBS10BTX),
        KUE_DEV(AOX, USB101),
        KUE_DEV(ASANTE, EA),
        KUE_DEV(ATEN, DSB650C),
        KUE_DEV(ATEN, UC10T),
        KUE_DEV(COREGA, ETHER_USB_T),
        KUE_DEV(DLINK, DSB650C),
        KUE_DEV(ENTREGA, E45),
        KUE_DEV(ENTREGA, XX1),
        KUE_DEV(ENTREGA, XX2),
        KUE_DEV(IODATA, USBETT),
        KUE_DEV(JATON, EDA),
        KUE_DEV(KINGSTON, XX1),
        KUE_DEV(KLSI, DUH3E10BT),
        KUE_DEV(KLSI, DUH3E10BTN),
        KUE_DEV(LINKSYS, USB10T),
        KUE_DEV(MOBILITY, EA),
        KUE_DEV(NETGEAR, EA101),
        KUE_DEV(NETGEAR, EA101X),
        KUE_DEV(PERACOM, ENET),
        KUE_DEV(PERACOM, ENET2),
        KUE_DEV(PERACOM, ENET3),
        KUE_DEV(PORTGEAR, EA8),
        KUE_DEV(PORTGEAR, EA9),
        KUE_DEV(PORTSMITH, EEA),
        KUE_DEV(SHARK, PA),
        KUE_DEV(SILICOM, GPE),
        KUE_DEV(SILICOM, U2E),
        KUE_DEV(SMC, 2102USB),
#undef KUE_DEV
};

/* prototypes */

static device_probe_t kue_probe;
static device_attach_t kue_attach;
static device_detach_t kue_detach;

static usb_callback_t kue_bulk_read_callback;
static usb_callback_t kue_bulk_write_callback;

static uether_fn_t kue_attach_post;
static uether_fn_t kue_init;
static uether_fn_t kue_stop;
static uether_fn_t kue_start;
static uether_fn_t kue_setmulti;
static uether_fn_t kue_setpromisc;

static int      kue_do_request(struct kue_softc *,
                    struct usb_device_request *, void *);
static int      kue_setword(struct kue_softc *, uint8_t, uint16_t);
static int      kue_ctl(struct kue_softc *, uint8_t, uint8_t, uint16_t,
                    void *, int);
static int      kue_load_fw(struct kue_softc *);
static void     kue_reset(struct kue_softc *);

#ifdef USB_DEBUG
static int kue_debug = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, kue, CTLFLAG_RW, 0, "USB kue");
SYSCTL_INT(_hw_usb_kue, OID_AUTO, debug, CTLFLAG_RWTUN, &kue_debug, 0,
    "Debug level");
#endif

static const struct usb_config kue_config[KUE_N_TRANSFER] = {

        [KUE_BULK_DT_WR] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = (MCLBYTES + 2 + 64),
                .flags = {.pipe_bof = 1,},
                .callback = kue_bulk_write_callback,
                .timeout = 10000,       /* 10 seconds */
        },

        [KUE_BULK_DT_RD] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = (MCLBYTES + 2),
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .callback = kue_bulk_read_callback,
                .timeout = 0,   /* no timeout */
        },
};

static device_method_t kue_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe, kue_probe),
        DEVMETHOD(device_attach, kue_attach),
        DEVMETHOD(device_detach, kue_detach),

        DEVMETHOD_END
};

static driver_t kue_driver = {
        .name = "kue",
        .methods = kue_methods,
        .size = sizeof(struct kue_softc),
};

static devclass_t kue_devclass;

DRIVER_MODULE(kue, uhub, kue_driver, kue_devclass, NULL, 0);
MODULE_DEPEND(kue, uether, 1, 1, 1);
MODULE_DEPEND(kue, usb, 1, 1, 1);
MODULE_DEPEND(kue, ether, 1, 1, 1);
MODULE_VERSION(kue, 1);
USB_PNP_HOST_INFO(kue_devs);

static const struct usb_ether_methods kue_ue_methods = {
        .ue_attach_post = kue_attach_post,
        .ue_start = kue_start,
        .ue_init = kue_init,
        .ue_stop = kue_stop,
        .ue_setmulti = kue_setmulti,
        .ue_setpromisc = kue_setpromisc,
};

/*
 * We have a custom do_request function which is almost like the
 * regular do_request function, except it has a much longer timeout.
 * Why? Because we need to make requests over the control endpoint
 * to download the firmware to the device, which can take longer
 * than the default timeout.
 */
static int
kue_do_request(struct kue_softc *sc, struct usb_device_request *req,
    void *data)
{
        usb_error_t err;

        err = uether_do_request(&sc->sc_ue, req, data, 60000);

        return (err);
}

static int
kue_setword(struct kue_softc *sc, uint8_t breq, uint16_t word)
{
        struct usb_device_request req;

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = breq;
        USETW(req.wValue, word);
        USETW(req.wIndex, 0);
        USETW(req.wLength, 0);

        return (kue_do_request(sc, &req, NULL));
}

static int
kue_ctl(struct kue_softc *sc, uint8_t rw, uint8_t breq,
    uint16_t val, void *data, int len)
{
        struct usb_device_request req;

        if (rw == KUE_CTL_WRITE)
                req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        else
                req.bmRequestType = UT_READ_VENDOR_DEVICE;


        req.bRequest = breq;
        USETW(req.wValue, val);
        USETW(req.wIndex, 0);
        USETW(req.wLength, len);

        return (kue_do_request(sc, &req, data));
}

static int
kue_load_fw(struct kue_softc *sc)
{
        struct usb_device_descriptor *dd;
        uint16_t hwrev;
        usb_error_t err;

        dd = usbd_get_device_descriptor(sc->sc_ue.ue_udev);
        hwrev = UGETW(dd->bcdDevice);

        /*
         * First, check if we even need to load the firmware.
         * If the device was still attached when the system was
         * rebooted, it may already have firmware loaded in it.
         * If this is the case, we don't need to do it again.
         * And in fact, if we try to load it again, we'll hang,
         * so we have to avoid this condition if we don't want
         * to look stupid.
         *
         * We can test this quickly by checking the bcdRevision
         * code. The NIC will return a different revision code if
         * it's probed while the firmware is still loaded and
         * running.
         */
        if (hwrev == 0x0202)
                return(0);

        /* Load code segment */
        err = kue_ctl(sc, KUE_CTL_WRITE, KUE_CMD_SEND_SCAN,
            0, kue_code_seg, sizeof(kue_code_seg));
        if (err) {
                device_printf(sc->sc_ue.ue_dev, "failed to load code segment: %s\n",
                    usbd_errstr(err));
                return(ENXIO);
        }

        /* Load fixup segment */
        err = kue_ctl(sc, KUE_CTL_WRITE, KUE_CMD_SEND_SCAN,
            0, kue_fix_seg, sizeof(kue_fix_seg));
        if (err) {
                device_printf(sc->sc_ue.ue_dev, "failed to load fixup segment: %s\n",
                    usbd_errstr(err));
                return(ENXIO);
        }

        /* Send trigger command. */
        err = kue_ctl(sc, KUE_CTL_WRITE, KUE_CMD_SEND_SCAN,
            0, kue_trig_seg, sizeof(kue_trig_seg));
        if (err) {
                device_printf(sc->sc_ue.ue_dev, "failed to load trigger segment: %s\n",
                    usbd_errstr(err));
                return(ENXIO);
        }

        return (0);
}

static void
kue_setpromisc(struct usb_ether *ue)
{
        struct kue_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        KUE_LOCK_ASSERT(sc, MA_OWNED);

        if (ifp->if_flags & IFF_PROMISC)
                sc->sc_rxfilt |= KUE_RXFILT_PROMISC;
        else
                sc->sc_rxfilt &= ~KUE_RXFILT_PROMISC;

        kue_setword(sc, KUE_CMD_SET_PKT_FILTER, sc->sc_rxfilt);
}

static void
kue_setmulti(struct usb_ether *ue)
{
        struct kue_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);
        struct ifmultiaddr *ifma;
        int i = 0;

        KUE_LOCK_ASSERT(sc, MA_OWNED);

        if (ifp->if_flags & IFF_ALLMULTI || ifp->if_flags & IFF_PROMISC) {
                sc->sc_rxfilt |= KUE_RXFILT_ALLMULTI;
                sc->sc_rxfilt &= ~KUE_RXFILT_MULTICAST;
                kue_setword(sc, KUE_CMD_SET_PKT_FILTER, sc->sc_rxfilt);
                return;
        }

        sc->sc_rxfilt &= ~KUE_RXFILT_ALLMULTI;

        if_maddr_rlock(ifp);
        TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
        {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                /*
                 * If there are too many addresses for the
                 * internal filter, switch over to allmulti mode.
                 */
                if (i == KUE_MCFILTCNT(sc))
                        break;
                memcpy(KUE_MCFILT(sc, i),
                    LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
                    ETHER_ADDR_LEN);
                i++;
        }
        if_maddr_runlock(ifp);

        if (i == KUE_MCFILTCNT(sc))
                sc->sc_rxfilt |= KUE_RXFILT_ALLMULTI;
        else {
                sc->sc_rxfilt |= KUE_RXFILT_MULTICAST;
                kue_ctl(sc, KUE_CTL_WRITE, KUE_CMD_SET_MCAST_FILTERS,
                    i, sc->sc_mcfilters, i * ETHER_ADDR_LEN);
        }

        kue_setword(sc, KUE_CMD_SET_PKT_FILTER, sc->sc_rxfilt);
}

/*
 * Issue a SET_CONFIGURATION command to reset the MAC. This should be
 * done after the firmware is loaded into the adapter in order to
 * bring it into proper operation.
 */
static void
kue_reset(struct kue_softc *sc)
{
        struct usb_config_descriptor *cd;
        usb_error_t err;

        cd = usbd_get_config_descriptor(sc->sc_ue.ue_udev);

        err = usbd_req_set_config(sc->sc_ue.ue_udev, &sc->sc_mtx,
            cd->bConfigurationValue);
        if (err)
                DPRINTF("reset failed (ignored)\n");

        /* wait a little while for the chip to get its brains in order */
        uether_pause(&sc->sc_ue, hz / 100);
}

static void
kue_attach_post(struct usb_ether *ue)
{
        struct kue_softc *sc = uether_getsc(ue);
        int error;

        /* load the firmware into the NIC */
        error = kue_load_fw(sc);
        if (error) {
                device_printf(sc->sc_ue.ue_dev, "could not load firmware\n");
                /* ignore the error */
        }

        /* reset the adapter */
        kue_reset(sc);

        /* read ethernet descriptor */
        kue_ctl(sc, KUE_CTL_READ, KUE_CMD_GET_ETHER_DESCRIPTOR,
            0, &sc->sc_desc, sizeof(sc->sc_desc));

        /* copy in ethernet address */
        memcpy(ue->ue_eaddr, sc->sc_desc.kue_macaddr, sizeof(ue->ue_eaddr));
}

/*
 * Probe for a KLSI chip.
 */
static int
kue_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);

        if (uaa->usb_mode != USB_MODE_HOST)
                return (ENXIO);
        if (uaa->info.bConfigIndex != KUE_CONFIG_IDX)
                return (ENXIO);
        if (uaa->info.bIfaceIndex != KUE_IFACE_IDX)
                return (ENXIO);

        return (usbd_lookup_id_by_uaa(kue_devs, sizeof(kue_devs), uaa));
}

/*
 * Attach the interface. Allocate softc structures, do
 * setup and ethernet/BPF attach.
 */
static int
kue_attach(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        struct kue_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;
        uint8_t iface_index;
        int error;

        device_set_usb_desc(dev);
        mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);

        iface_index = KUE_IFACE_IDX;
        error = usbd_transfer_setup(uaa->device, &iface_index,
            sc->sc_xfer, kue_config, KUE_N_TRANSFER, sc, &sc->sc_mtx);
        if (error) {
                device_printf(dev, "allocating USB transfers failed\n");
                goto detach;
        }

        sc->sc_mcfilters = malloc(KUE_MCFILTCNT(sc) * ETHER_ADDR_LEN,
            M_USBDEV, M_WAITOK);
        if (sc->sc_mcfilters == NULL) {
                device_printf(dev, "failed allocating USB memory\n");
                goto detach;
        }

        ue->ue_sc = sc;
        ue->ue_dev = dev;
        ue->ue_udev = uaa->device;
        ue->ue_mtx = &sc->sc_mtx;
        ue->ue_methods = &kue_ue_methods;

        error = uether_ifattach(ue);
        if (error) {
                device_printf(dev, "could not attach interface\n");
                goto detach;
        }
        return (0);                     /* success */

detach:
        kue_detach(dev);
        return (ENXIO);                 /* failure */
}

static int
kue_detach(device_t dev)
{
        struct kue_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;

        usbd_transfer_unsetup(sc->sc_xfer, KUE_N_TRANSFER);
        uether_ifdetach(ue);
        mtx_destroy(&sc->sc_mtx);
        free(sc->sc_mcfilters, M_USBDEV);

        return (0);
}

/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static void
kue_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct kue_softc *sc = usbd_xfer_softc(xfer);
        struct usb_ether *ue = &sc->sc_ue;
        struct ifnet *ifp = uether_getifp(ue);
        struct usb_page_cache *pc;
        uint8_t buf[2];
        int len;
        int actlen;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                if (actlen <= (int)(2 + sizeof(struct ether_header))) {
                        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                        goto tr_setup;
                }
                pc = usbd_xfer_get_frame(xfer, 0);
                usbd_copy_out(pc, 0, buf, 2);
                actlen -= 2;
                len = buf[0] | (buf[1] << 8);
                len = min(actlen, len);

                uether_rxbuf(ue, pc, 2, len);
                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
                usbd_transfer_submit(xfer);
                uether_rxflush(ue);
                return;

        default:                        /* Error */
                DPRINTF("bulk read error, %s\n",
                    usbd_errstr(error));

                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;

        }
}

static void
kue_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct kue_softc *sc = usbd_xfer_softc(xfer);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        struct usb_page_cache *pc;
        struct mbuf *m;
        int total_len;
        int temp_len;
        uint8_t buf[2];

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                DPRINTFN(11, "transfer complete\n");
                if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);

                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                IFQ_DRV_DEQUEUE(&ifp->if_snd, m);

                if (m == NULL)
                        return;
                if (m->m_pkthdr.len > MCLBYTES)
                        m->m_pkthdr.len = MCLBYTES;
                temp_len = (m->m_pkthdr.len + 2);
                total_len = (temp_len + (64 - (temp_len % 64)));

                /* the first two bytes are the frame length */

                buf[0] = (uint8_t)(m->m_pkthdr.len);
                buf[1] = (uint8_t)(m->m_pkthdr.len >> 8);

                pc = usbd_xfer_get_frame(xfer, 0);
                usbd_copy_in(pc, 0, buf, 2);
                usbd_m_copy_in(pc, 2, m, 0, m->m_pkthdr.len);

                usbd_frame_zero(pc, temp_len, total_len - temp_len);
                usbd_xfer_set_frame_len(xfer, 0, total_len);

                /*
                 * if there's a BPF listener, bounce a copy
                 * of this frame to him:
                 */
                BPF_MTAP(ifp, m);

                m_freem(m);

                usbd_transfer_submit(xfer);

                return;

        default:                        /* Error */
                DPRINTFN(11, "transfer error, %s\n",
                    usbd_errstr(error));

                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);

                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;

        }
}

static void
kue_start(struct usb_ether *ue)
{
        struct kue_softc *sc = uether_getsc(ue);

        /*
         * start the USB transfers, if not already started:
         */
        usbd_transfer_start(sc->sc_xfer[KUE_BULK_DT_RD]);
        usbd_transfer_start(sc->sc_xfer[KUE_BULK_DT_WR]);
}

static void
kue_init(struct usb_ether *ue)
{
        struct kue_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        KUE_LOCK_ASSERT(sc, MA_OWNED);

        /* set MAC address */
        kue_ctl(sc, KUE_CTL_WRITE, KUE_CMD_SET_MAC,
            0, IF_LLADDR(ifp), ETHER_ADDR_LEN);

        /* I'm not sure how to tune these. */
#if 0
        /*
         * Leave this one alone for now; setting it
         * wrong causes lockups on some machines/controllers.
         */
        kue_setword(sc, KUE_CMD_SET_SOFS, 1);
#endif
        kue_setword(sc, KUE_CMD_SET_URB_SIZE, 64);

        /* load the multicast filter */
        kue_setpromisc(ue);

        usbd_xfer_set_stall(sc->sc_xfer[KUE_BULK_DT_WR]);

        ifp->if_drv_flags |= IFF_DRV_RUNNING;
        kue_start(ue);
}

static void
kue_stop(struct usb_ether *ue)
{
        struct kue_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        KUE_LOCK_ASSERT(sc, MA_OWNED);

        ifp->if_drv_flags &= ~IFF_DRV_RUNNING;

        /*
         * stop all the transfers, if not already stopped:
         */
        usbd_transfer_stop(sc->sc_xfer[KUE_BULK_DT_WR]);
        usbd_transfer_stop(sc->sc_xfer[KUE_BULK_DT_RD]);
}