again some little changes (diff between my and matteo's code)

[acx-mac80211.git] / usb.c

/**** (legal) claimer in README
** Copyright (C) 2003  ACX100 Open Source Project
*/

/***********************************************************************
** USB support for TI ACX100 based devices. Many parts are taken from
** the PCI driver.
**
** Authors:
**  Martin Wawro <martin.wawro AT uni-dortmund.de>
**  Andreas Mohr <andi AT lisas.de>
**
** LOCKING
** callback functions called by USB core are running in interrupt context
** and thus have names with _i_.
*/
#define ACX_MAC80211_USB 1

#include <linux/version.h>
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
#include <linux/config.h>
#endif
#include <linux/types.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
#include <linux/wireless.h>
#include <net/iw_handler.h>
#include <linux/vmalloc.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>

#include "acx.h"


/***********************************************************************
*/
/* number of endpoints of an interface */
#define NUM_EP(intf) (intf)->altsetting[0].desc.bNumEndpoints
#define EP(intf, nr) (intf)->altsetting[0].endpoint[(nr)].desc
#define GET_DEV(udev) usb_get_dev((udev))
#define PUT_DEV(udev) usb_put_dev((udev))

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
/* removed in 2.6.14. We will use fake value for now */
#define URB_ASYNC_UNLINK 0
#endif


/***********************************************************************
*/
/* ACX100 (TNETW1100) USB device: D-Link DWL-120+ */
#define ACX100_VENDOR_ID 0x2001
#define ACX100_PRODUCT_ID_UNBOOTED 0x3B01
#define ACX100_PRODUCT_ID_BOOTED 0x3B00

/* TNETW1450 USB devices */
#define VENDOR_ID_DLINK         0x07b8  /* D-Link Corp. */
#define PRODUCT_ID_WUG2400      0xb21a  /* AboCom WUG2400 or SafeCom SWLUT-54125 */
#define VENDOR_ID_AVM_GMBH      0x057c
#define PRODUCT_ID_AVM_WLAN_USB 0x5601
#define PRODUCT_ID_AVM_WLAN_USB_si      0x6201  /* "self install" named Version: 
                                                 * driver kills kernel on inbound scans from fritz box ??  */
#define VENDOR_ID_ZCOM          0x0cde
#define PRODUCT_ID_ZCOM_XG750   0x0017  /* not tested yet */
#define VENDOR_ID_TI            0x0451
#define PRODUCT_ID_TI_UNKNOWN   0x60c5  /* not tested yet */

#define ACX_USB_CTRL_TIMEOUT    5500    /* steps in ms */

/* Buffer size for fw upload, same for both ACX100 USB and TNETW1450 */
#define USB_RWMEM_MAXLEN        2048

/* The number of bulk URBs to use */
#define ACX_TX_URB_CNT          8
#define ACX_RX_URB_CNT          2

/* Should be sent to the bulkout endpoint */
#define ACX_USB_REQ_UPLOAD_FW   0x10
#define ACX_USB_REQ_ACK_CS      0x11
#define ACX_USB_REQ_CMD         0x12

/***********************************************************************
** Prototypes
*/
static int acxusb_e_probe(struct usb_interface *, const struct usb_device_id *);
static void acxusb_e_disconnect(struct usb_interface *);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19)
static void acxusb_i_complete_tx(struct urb *);
static void acxusb_i_complete_rx(struct urb *);
#else
static void acxusb_i_complete_tx(struct urb *, struct pt_regs *);
static void acxusb_i_complete_rx(struct urb *, struct pt_regs *);
#endif
static int acxusb_e_open(struct ieee80211_hw *);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
static int acxusb_e_close(struct ieee80211_hw *);
#else
static void acxusb_e_close(struct ieee80211_hw *);
#endif
//static void acxusb_i_set_rx_mode(struct net_device *);
static int acxusb_boot(struct usb_device *, int is_tnetw1450, int *radio_type);

static void acxusb_l_poll_rx(acx_device_t * adev, usb_rx_t * rx);

/*static void acxusb_i_tx_timeout(struct net_device *);*/

/* static void dump_device(struct usb_device *); */
/* static void dump_device_descriptor(struct usb_device_descriptor *); */
/* static void dump_config_descriptor(struct usb_config_descriptor *); */

/***********************************************************************
** Module Data
*/
#define TXBUFSIZE sizeof(usb_txbuffer_t)
/*
 * Now, this is just plain lying, but the device insists in giving us
 * huge packets. We supply extra space after rxbuffer. Need to understand
 * it better...
 */
#define RXBUFSIZE (sizeof(rxbuffer_t) + \
                   (sizeof(usb_rx_t) - sizeof(struct usb_rx_plain)))

static const struct usb_device_id acxusb_ids[] = {
        {USB_DEVICE(ACX100_VENDOR_ID, ACX100_PRODUCT_ID_BOOTED)},
        {USB_DEVICE(ACX100_VENDOR_ID, ACX100_PRODUCT_ID_UNBOOTED)},
        {USB_DEVICE(VENDOR_ID_DLINK, PRODUCT_ID_WUG2400)},
        {USB_DEVICE(VENDOR_ID_AVM_GMBH, PRODUCT_ID_AVM_WLAN_USB)},
        {USB_DEVICE(VENDOR_ID_AVM_GMBH, PRODUCT_ID_AVM_WLAN_USB_si)},
        {USB_DEVICE(VENDOR_ID_ZCOM, PRODUCT_ID_ZCOM_XG750)},
        {USB_DEVICE(VENDOR_ID_TI, PRODUCT_ID_TI_UNKNOWN)},
        {}
};

MODULE_DEVICE_TABLE(usb, acxusb_ids);

/* USB driver data structure as required by the kernel's USB core */
static struct usb_driver
 acxusb_driver = {
        .name = "acx_usb",
        .probe = acxusb_e_probe,
        .disconnect = acxusb_e_disconnect,
        .id_table = acxusb_ids
};

void acxusb_put_devname(acx_device_t *adev, struct ethtool_drvinfo *info)
{

        usb_make_path(adev->usbdev, info->bus_info, sizeof info->bus_info);
}
/***********************************************************************
** USB helper
**
** ldd3 ch13 says:
** When the function is usb_kill_urb, the urb lifecycle is stopped. This
** function is usually used when the device is disconnected from the system,
** in the disconnect callback. For some drivers, the usb_unlink_urb function
** should be used to tell the USB core to stop an urb. This function does not
** wait for the urb to be fully stopped before returning to the caller.
** This is useful for stoppingthe urb while in an interrupt handler or when
** a spinlock is held, as waiting for a urb to fully stop requires the ability
** for the USB core to put the calling process to sleep. This function requires
** that the URB_ASYNC_UNLINK flag value be set in the urb that is being asked
** to be stopped in order to work properly.
**
** (URB_ASYNC_UNLINK is obsolete, usb_unlink_urb will always be
** asynchronous while usb_kill_urb is synchronous and should be called
** directly (drivers/usb/core/urb.c))
**
** In light of this, timeout is just for paranoid reasons...
*
** Actually, it's useful for debugging. If we reach timeout, we're doing
** something wrong with the urbs.
*/
static void acxusb_unlink_urb(struct urb *urb)
{
        if (!urb)
                return;

        if (urb->status == -EINPROGRESS) {
                int timeout = 10;

                usb_unlink_urb(urb);
                while (--timeout && urb->status == -EINPROGRESS) {
                        mdelay(1);
                }
                if (!timeout) {
                        printk(KERN_ERR "acx_usb: urb unlink timeout!\n");
                }
        }
}


/***********************************************************************
** EEPROM and PHY read/write helpers
*/
/***********************************************************************
** acxusb_s_read_phy_reg
*/
int acxusb_s_read_phy_reg(acx_device_t * adev, u32 reg, u8 * charbuf)
{
        /* mem_read_write_t mem; */

        FN_ENTER;

        printk("%s doesn't seem to work yet, disabled.\n", __func__);

        /*
           mem.addr = cpu_to_le16(reg);
           mem.type = cpu_to_le16(0x82);
           mem.len = cpu_to_le32(4);
           acx_s_issue_cmd(adev, ACX1xx_CMD_MEM_READ, &mem, sizeof(mem));
           *charbuf = mem.data;
           log(L_DEBUG, "read radio PHY[0x%04X]=0x%02X\n", reg, *charbuf);
         */

        FN_EXIT1(OK);
        return OK;
}


/***********************************************************************
*/
int acxusb_s_write_phy_reg(acx_device_t * adev, u32 reg, u8 value)
{
        mem_read_write_t mem;

        FN_ENTER;

        mem.addr = cpu_to_le16(reg);
        mem.type = cpu_to_le16(0x82);
        mem.len = cpu_to_le32(4);
        mem.data = value;
        acx_s_issue_cmd(adev, ACX1xx_CMD_MEM_WRITE, &mem, sizeof(mem));
        log(L_DEBUG, "write radio PHY[0x%04X]=0x%02X\n", reg, value);

        FN_EXIT1(OK);
        return OK;
}


/***********************************************************************
** acxusb_s_issue_cmd_timeo
** Excecutes a command in the command mailbox
**
** buffer = a pointer to the data.
** The data must not include 4 byte command header
*/

/* TODO: ideally we shall always know how much we need
** and this shall be 0 */
#define BOGUS_SAFETY_PADDING 0x40

#undef FUNC
#define FUNC "issue_cmd"

#if !ACX_DEBUG
int
acxusb_s_issue_cmd_timeo(acx_device_t * adev,
                         unsigned cmd,
                         void *buffer, unsigned buflen, unsigned timeout)
{
#else
int
acxusb_s_issue_cmd_timeo_debug(acx_device_t * adev,
                               unsigned cmd,
                               void *buffer,
                               unsigned buflen,
                               unsigned timeout, const char *cmdstr)
{
#endif
        /* USB ignores timeout param */

        struct usb_device *usbdev;
        struct {
                u16 cmd;
                u16 status;
                u8 data[1];
        } ACX_PACKED *loc;
        const char *devname;
        int acklen, blocklen, inpipe, outpipe;
        int cmd_status;
        int result;

        FN_ENTER;

        devname = wiphy_name(adev->ieee->wiphy);
        /* no "wlan%%d: ..." please */
        if (!devname || !devname[0] || devname[4] == '%')
                devname = "acx";

        log(L_CTL, FUNC "(cmd:%s,buflen:%u,type:0x%04X)\n",
            cmdstr, buflen,
            buffer ? le16_to_cpu(((acx_ie_generic_t *) buffer)->type) : -1);

        loc = kmalloc(buflen + 4 + BOGUS_SAFETY_PADDING, GFP_KERNEL);
        if (!loc) {
                printk("%s: " FUNC "(): no memory for data buffer\n", devname);
                goto bad;
        }

        /* get context from acx_device */
        usbdev = adev->usbdev;

        /* check which kind of command was issued */
        loc->cmd = cpu_to_le16(cmd);
        loc->status = 0;

/* NB: buflen == frmlen + 4
**
** Interrogate: write 8 bytes: (cmd,status,rid,frmlen), then
**              read (cmd,status,rid,frmlen,data[frmlen]) back
**
** Configure: write (cmd,status,rid,frmlen,data[frmlen])
**
** Possibly bogus special handling of ACX1xx_IE_SCAN_STATUS removed
*/

        /* now write the parameters of the command if needed */
        acklen = buflen + 4 + BOGUS_SAFETY_PADDING;
        blocklen = buflen;
        if (buffer && buflen) {
                /* if it's an INTERROGATE command, just pass the length
                 * of parameters to read, as data */
                if (cmd == ACX1xx_CMD_INTERROGATE) {
                        blocklen = 4;
                        acklen = buflen + 4;
                }
                memcpy(loc->data, buffer, blocklen);
        }
        blocklen += 4;          /* account for cmd,status */

        /* obtain the I/O pipes */
        outpipe = usb_sndctrlpipe(usbdev, 0);
        inpipe = usb_rcvctrlpipe(usbdev, 0);
        log(L_CTL, "ctrl inpipe=0x%X outpipe=0x%X\n", inpipe, outpipe);
        log(L_CTL, "sending USB control msg (out) (blocklen=%d)\n", blocklen);
        if (acx_debug & L_DATA)
                acx_dump_bytes(loc, blocklen);

        result = usb_control_msg(usbdev, outpipe, ACX_USB_REQ_CMD,      /* request */
                                 USB_TYPE_VENDOR | USB_DIR_OUT, /* requesttype */
                                 0,     /* value */
                                 0,     /* index */
                                 loc,   /* dataptr */
                                 blocklen,      /* size */
                                 ACX_USB_CTRL_TIMEOUT   /* timeout in ms */
            );

        if (result == -ENODEV) {
                log(L_CTL, "no device present (unplug?)\n");
                goto good;
        }

        log(L_CTL, "wrote %d bytes\n", result);
        if (result < 0) {
                goto bad;
        }

        /* check for device acknowledge */
        log(L_CTL, "sending USB control msg (in) (acklen=%d)\n", acklen);
        loc->status = 0;        /* delete old status flag -> set to IDLE */
        /* shall we zero out the rest? */
        result = usb_control_msg(usbdev, inpipe, ACX_USB_REQ_CMD,       /* request */
                                 USB_TYPE_VENDOR | USB_DIR_IN,  /* requesttype */
                                 0,     /* value */
                                 0,     /* index */
                                 loc,   /* dataptr */
                                 acklen,        /* size */
                                 ACX_USB_CTRL_TIMEOUT   /* timeout in ms */
            );
        if (result < 0) {
                printk("%s: " FUNC "(): USB read error %d\n", devname, result);
                goto bad;
        }
        if (acx_debug & L_CTL) {
                printk("read %d bytes: ", result);
                acx_dump_bytes(loc, result);
        }

/*
   check for result==buflen+4? Was seen:

interrogate(type:ACX100_IE_DOT11_ED_THRESHOLD,len:4)
issue_cmd(cmd:ACX1xx_CMD_INTERROGATE,buflen:8,type:4111)
ctrl inpipe=0x80000280 outpipe=0x80000200
sending USB control msg (out) (blocklen=8)
01 00 00 00 0F 10 04 00
wrote 8 bytes
sending USB control msg (in) (acklen=12) sizeof(loc->data
read 4 bytes <==== MUST BE 12!!
*/

        cmd_status = le16_to_cpu(loc->status);
        if (cmd_status != 1) {
                printk("%s: " FUNC "(): cmd_status is not SUCCESS: %d (%s)\n",
                       devname, cmd_status, acx_cmd_status_str(cmd_status));
                /* TODO: goto bad; ? */
        }
        if ((cmd == ACX1xx_CMD_INTERROGATE) && buffer && buflen) {
                memcpy(buffer, loc->data, buflen);
                log(L_CTL, "response frame: cmd=0x%04X status=%d\n",
                    le16_to_cpu(loc->cmd), cmd_status);
        }
      good:
        kfree(loc);
        FN_EXIT1(OK);
        return OK;
      bad:
        /* Give enough info so that callers can avoid
         ** printing their own diagnostic messages */
#if ACX_DEBUG
        printk("%s: " FUNC "(cmd:%s) FAILED\n", devname, cmdstr);
#else
        printk("%s: " FUNC "(cmd:0x%04X) FAILED\n", devname, cmd);
#endif
        dump_stack();
        kfree(loc);
        FN_EXIT1(NOT_OK);
        return NOT_OK;
}


/***********************************************************************
** acxusb_boot()
** Inputs:
**    usbdev -> Pointer to kernel's usb_device structure
**
** Returns:
**  (int) Errorcode or 0 on success
**
** This function triggers the loading of the firmware image from harddisk
** and then uploads the firmware to the USB device. After uploading the
** firmware and transmitting the checksum, the device resets and appears
** as a new device on the USB bus (the device we can finally deal with)
*/
static inline int
acxusb_fw_needs_padding(firmware_image_t *fw_image, unsigned int usb_maxlen)
{
        unsigned int num_xfers = ((fw_image->size - 1) / usb_maxlen) + 1;

        return ((num_xfers % 2) == 0);
}

static int
acxusb_boot(struct usb_device *usbdev, int is_tnetw1450, int *radio_type)
{
        char filename[sizeof("tiacx1NNusbcRR")];

        firmware_image_t *fw_image = NULL;
        char *usbbuf;
        unsigned int offset;
        unsigned int blk_len, inpipe, outpipe;
        u32 num_processed;
        u32 img_checksum, sum;
        u32 file_size;
        int result = -EIO;
        int i;

        FN_ENTER;

        /* dump_device(usbdev); */

        usbbuf = kmalloc(USB_RWMEM_MAXLEN, GFP_KERNEL);
        if (!usbbuf) {
                printk(KERN_ERR
                       "acx: no memory for USB transfer buffer (%d bytes)\n",
                       USB_RWMEM_MAXLEN);
                result = -ENOMEM;
                goto end;
        }
        if (is_tnetw1450) {
                /* Obtain the I/O pipes */
                outpipe = usb_sndbulkpipe(usbdev, 1);
                inpipe = usb_rcvbulkpipe(usbdev, 2);

                printk(KERN_DEBUG "wait for device ready\n");
                for (i = 0; i <= 2; i++) {
                        result = usb_bulk_msg(usbdev, inpipe,
                                              usbbuf,
                                              USB_RWMEM_MAXLEN,
                                              &num_processed, 2000);

                        if ((*(u32 *) & usbbuf[4] == 0x40000001)
                            && (*(u16 *) & usbbuf[2] == 0x1)
                            && ((*(u16 *) usbbuf & 0x3fff) == 0)
                            && ((*(u16 *) usbbuf & 0xc000) == 0xc000))
                                break;
                        acx_s_mwait(10);
                }
                if (i == 2)
                        goto fw_end;

                *radio_type = usbbuf[8];
        } else {
                /* Obtain the I/O pipes */
                outpipe = usb_sndctrlpipe(usbdev, 0);
                inpipe = usb_rcvctrlpipe(usbdev, 0);

                /* FIXME: shouldn't be hardcoded */
                *radio_type = RADIO_MAXIM_0D;
        }

        snprintf(filename, sizeof(filename), "tiacx1%02dusbc%02X",
                 is_tnetw1450 * 11, *radio_type);

        fw_image = acx_s_read_fw(&usbdev->dev, filename, &file_size);
        if (!fw_image) {
                result = -EIO;
                goto end;
        }
        log(L_INIT, "firmware size: %d bytes\n", file_size);

        img_checksum = le32_to_cpu(fw_image->chksum);

        if (is_tnetw1450) {
                u8 cmdbuf[20];
                const u8 *p;
                u8 need_padding;
                u32 tmplen, val;

                memset(cmdbuf, 0, 16);

                need_padding =
                    acxusb_fw_needs_padding(fw_image, USB_RWMEM_MAXLEN);
                tmplen = need_padding ? file_size - 4 : file_size - 8;
                *(u16 *) & cmdbuf[0] = 0xc000;
                *(u16 *) & cmdbuf[2] = 0x000b;
                *(u32 *) & cmdbuf[4] = tmplen;
                *(u32 *) & cmdbuf[8] = file_size - 8;
                *(u32 *) & cmdbuf[12] = img_checksum;

                result =
                    usb_bulk_msg(usbdev, outpipe, cmdbuf, 16, &num_processed,
                                 HZ);
                if (result < 0)
                        goto fw_end;

                p = (const u8 *)&fw_image->size;

                /* first calculate checksum for image size part */
                sum = p[0] + p[1] + p[2] + p[3];
                p += 4;

                /* now continue checksum for firmware data part */
                tmplen = le32_to_cpu(fw_image->size);
                for (i = 0; i < tmplen /* image size */ ; i++) {
                        sum += *p++;
                }

                if (sum != le32_to_cpu(fw_image->chksum)) {
                        printk("acx: FATAL: firmware upload: "
                               "checksums don't match! "
                               "(0x%08x vs. 0x%08x)\n", sum, fw_image->chksum);
                        goto fw_end;
                }

                offset = 8;
                while (offset < file_size) {
                        blk_len = file_size - offset;
                        if (blk_len > USB_RWMEM_MAXLEN) {
                                blk_len = USB_RWMEM_MAXLEN;
                        }

                        log(L_INIT,
                            "uploading firmware (%d bytes, offset=%d)\n",
                            blk_len, offset);
                        memcpy(usbbuf, ((u8 *) fw_image) + offset, blk_len);

                        p = usbbuf;
                        for (i = 0; i < blk_len; i += 4) {
                                *(u32 *) p = be32_to_cpu(*(u32 *) p);
                                p += 4;
                        }

                        result =
                            usb_bulk_msg(usbdev, outpipe, usbbuf, blk_len,
                                         &num_processed, HZ);
                        if ((result < 0) || (num_processed != blk_len))
                                goto fw_end;
                        offset += blk_len;
                }
                if (need_padding) {
                        printk(KERN_DEBUG "send padding\n");
                        memset(usbbuf, 0, 4);
                        result =
                            usb_bulk_msg(usbdev, outpipe, usbbuf, 4,
                                         &num_processed, HZ);
                        if ((result < 0) || (num_processed != 4))
                                goto fw_end;
                }
                printk(KERN_DEBUG "read firmware upload result\n");
                memset(cmdbuf, 0, 20);  /* additional memset */
                result =
                    usb_bulk_msg(usbdev, inpipe, cmdbuf, 20, &num_processed,
                                 2000);
                if (result < 0)
                        goto fw_end;
                if (*(u32 *) & cmdbuf[4] == 0x40000003)
                        goto fw_end;
                if (*(u32 *) & cmdbuf[4])
                        goto fw_end;
                if (*(u16 *) & cmdbuf[16] != 1)
                        goto fw_end;

                val = *(u32 *) & cmdbuf[0];
                if ((val & 0x3fff)
                    || ((val & 0xc000) != 0xc000))
                        goto fw_end;

                val = *(u32 *) & cmdbuf[8];
                if (val & 2) {
                        result =
                            usb_bulk_msg(usbdev, inpipe, cmdbuf, 20,
                                         &num_processed, 2000);
                        if (result < 0)
                                goto fw_end;
                        val = *(u32 *) & cmdbuf[8];
                }
                /* yup, no "else" here! */
                if (val & 1) {
                        memset(usbbuf, 0, 4);
                        result =
                            usb_bulk_msg(usbdev, outpipe, usbbuf, 4,
                                         &num_processed, HZ);
                        if ((result < 0) || (!num_processed))
                                goto fw_end;
                }

                printk("TNETW1450 firmware upload successful!\n");
                result = 0;
                goto end;
              fw_end:
                result = -EIO;
                goto end;
        } else {
                /* ACX100 USB */

                /* now upload the firmware, slice the data into blocks */
                offset = 8;
                while (offset < file_size) {
                        blk_len = file_size - offset;
                        if (blk_len > USB_RWMEM_MAXLEN) {
                                blk_len = USB_RWMEM_MAXLEN;
                        }
                        log(L_INIT,
                            "uploading firmware (%d bytes, offset=%d)\n",
                            blk_len, offset);
                        memcpy(usbbuf, ((u8 *) fw_image) + offset, blk_len);
                        result = usb_control_msg(usbdev, outpipe, ACX_USB_REQ_UPLOAD_FW, USB_TYPE_VENDOR | USB_DIR_OUT, (file_size - 8) & 0xffff,       /* value */
                                                 (file_size - 8) >> 16, /* index */
                                                 usbbuf,        /* dataptr */
                                                 blk_len,       /* size */
                                                 3000   /* timeout in ms */
                            );
                        offset += blk_len;
                        if (result < 0) {
                                printk(KERN_ERR "acx: error %d during upload "
                                       "of firmware, aborting\n", result);
                                goto end;
                        }
                }

                /* finally, send the checksum and reboot the device */
                /* does this trigger the reboot? */
                result = usb_control_msg(usbdev, outpipe, ACX_USB_REQ_UPLOAD_FW, USB_TYPE_VENDOR | USB_DIR_OUT, img_checksum & 0xffff,  /* value */
                                         img_checksum >> 16,    /* index */
                                         NULL,  /* dataptr */
                                         0,     /* size */
                                         3000   /* timeout in ms */
                    );
                if (result < 0) {
                        printk(KERN_ERR "acx: error %d during tx of checksum, "
                               "aborting\n", result);
                        goto end;
                }
                result = usb_control_msg(usbdev, inpipe, ACX_USB_REQ_ACK_CS, USB_TYPE_VENDOR | USB_DIR_IN, img_checksum & 0xffff,       /* value */
                                         img_checksum >> 16,    /* index */
                                         usbbuf,        /* dataptr */
                                         8,     /* size */
                                         3000   /* timeout in ms */
                    );
                if (result < 0) {
                        printk(KERN_ERR "acx: error %d during ACK of checksum, "
                               "aborting\n", result);
                        goto end;
                }
                if (*usbbuf != 0x10) {
                        printk(KERN_ERR "acx: invalid checksum?\n");
                        result = -EINVAL;
                        goto end;
                }
                result = 0;
        }

      end:
        vfree(fw_image);
        kfree(usbbuf);

        FN_EXIT1(result);
        return result;
}


/* FIXME: maybe merge it with usual eeprom reading, into common code? */
static void acxusb_s_read_eeprom_version(acx_device_t * adev)
{
        u8 eeprom_ver[0x8];

        memset(eeprom_ver, 0, sizeof(eeprom_ver));
        acx_s_interrogate(adev, &eeprom_ver, ACX1FF_IE_EEPROM_VER);

        /* FIXME: which one of those values to take? */
        adev->eeprom_version = eeprom_ver[5];
}


/*
 * temporary helper function to at least fill important cfgopt members with
 * useful replacement values until we figure out how one manages to fetch
 * the configoption struct in the USB device case...
 */
static int acxusb_s_fill_configoption(acx_device_t * adev)
{
        adev->cfgopt_probe_delay = 200;
        adev->cfgopt_dot11CCAModes = 4;
        adev->cfgopt_dot11Diversity = 1;
        adev->cfgopt_dot11ShortPreambleOption = 1;
        adev->cfgopt_dot11PBCCOption = 1;
        adev->cfgopt_dot11ChannelAgility = 0;
        adev->cfgopt_dot11PhyType = 5;
        adev->cfgopt_dot11TempType = 1;
        return OK;
}

static const struct ieee80211_ops acxusb_hw_ops = {
        .tx = acx_i_start_xmit,
        .conf_tx = acx_net_conf_tx,
        .add_interface = acx_add_interface,
        .remove_interface = acx_remove_interface,
        #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
        .open = acxusb_e_open,
        .reset = acx_net_reset,
        .set_multicast_list = acx_i_set_multicast_list,
        #else
        .start = acxusb_e_open,
        .configure_filter = acx_i_set_multicast_list,
        #endif
        .stop = acxusb_e_close,
        .config = acx_net_config,
        .config_interface = acx_config_interface,
        .set_key = acx_net_set_key,         
        .get_stats = acx_e_get_stats,
        .get_tx_stats = acx_net_get_tx_stats,
};

/***********************************************************************
** acxusb_e_probe()
**
** This function is invoked by the kernel's USB core whenever a new device is
** attached to the system or the module is loaded. It is presented a usb_device
** structure from which information regarding the device is obtained and evaluated.
** In case this driver is able to handle one of the offered devices, it returns
** a non-null pointer to a driver context and thereby claims the device.
*/


static int
acxusb_e_probe(struct usb_interface *intf, const struct usb_device_id *devID)
{
        struct usb_device *usbdev = interface_to_usbdev(intf);
        acx_device_t *adev = NULL;
        struct usb_config_descriptor *config;
        struct usb_endpoint_descriptor *epdesc;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
        struct usb_host_endpoint *ep;
#endif
        struct usb_interface_descriptor *ifdesc;
        const char *msg;
        int numconfigs, numfaces, numep;
        int result = OK;
        int i;
        int radio_type;
        /* this one needs to be more precise in case there appears
         * a TNETW1450 from the same vendor */
        int is_tnetw1450 = (usbdev->descriptor.idVendor != ACX100_VENDOR_ID);
        struct ieee80211_hw *ieee;

        FN_ENTER;

        if (is_tnetw1450) {
                /* Boot the device (i.e. upload the firmware) */
                acxusb_boot(usbdev, is_tnetw1450, &radio_type);

                /* TNETW1450-based cards will continue right away with
                 * the same USB ID after booting */
        } else {
                /* First check if this is the "unbooted" hardware */
                if (usbdev->descriptor.idProduct == ACX100_PRODUCT_ID_UNBOOTED) {

                        /* Boot the device (i.e. upload the firmware) */
                        acxusb_boot(usbdev, is_tnetw1450, &radio_type);

                        /* DWL-120+ will first boot the firmware,
                         * then later have a *separate* probe() run
                         * since its USB ID will have changed after
                         * firmware boot!
                         * Since the first probe() run has no
                         * other purpose than booting the firmware,
                         * simply return immediately.
                         */
                        log(L_INIT,
                            "finished booting, returning from probe()\n");
                        result = OK;    /* success */
                        goto end;
                } else {
                        if (usbdev->descriptor.idProduct != ACX100_PRODUCT_ID_BOOTED)
                                /* device not unbooted, but invalid USB ID!? */
                                goto end_nodev;
                }
        }

/* Ok, so it's our device and it has already booted */

        /* Allocate memory for a network device */

        ieee = ieee80211_alloc_hw(sizeof(*adev), &acxusb_hw_ops);
        if (!ieee) {
                msg = "acx: no memory for ieee80211_dev\n";
                goto end_nomem;
        }


        ieee->flags &=   ~IEEE80211_HW_RX_INCLUDES_FCS;
                        /* TODO: mainline doesn't support the following flags yet */
                        /*
                          ~IEEE80211_HW_MONITOR_DURING_OPER &
                          ~IEEE80211_HW_WEP_INCLUDE_IV;
                        */
        ieee->queues = 1;

        /* Register the callbacks for the network device functions */


        /* Setup private driver context */

        adev = ieee2adev(ieee);
        adev->ieee = ieee;
        
        adev->dev_type = DEVTYPE_USB;
        adev->radio_type = radio_type;
        if (is_tnetw1450) {
                /* well, actually it's a TNETW1450, but since it
                 * seems to be sufficiently similar to TNETW1130,
                 * I don't want to change large amounts of code now */
                adev->chip_type = CHIPTYPE_ACX111;
        } else {
                adev->chip_type = CHIPTYPE_ACX100;
        }

        adev->usbdev = usbdev;
        spin_lock_init(&adev->lock);    /* initial state: unlocked */
        mutex_init(&adev->mutex);

        /* Check that this is really the hardware we know about.
         ** If not sure, at least notify the user that he
         ** may be in trouble...
         */
        numconfigs = (int)usbdev->descriptor.bNumConfigurations;
        if (numconfigs != 1)
                printk("acx: number of configurations is %d, "
                       "this driver only knows how to handle 1, "
                       "be prepared for surprises\n", numconfigs);

        config = &usbdev->config->desc;
        numfaces = config->bNumInterfaces;
        if (numfaces != 1)
                printk("acx: number of interfaces is %d, "
                       "this driver only knows how to handle 1, "
                       "be prepared for surprises\n", numfaces);

        ifdesc = &intf->altsetting->desc;
        numep = ifdesc->bNumEndpoints;
        log(L_DEBUG, "# of endpoints: %d\n", numep);

        if (is_tnetw1450) {
                adev->bulkoutep = 1;
                adev->bulkinep = 2;
        } else {
                /* obtain information about the endpoint
                 ** addresses, begin with some default values
                 */
                adev->bulkoutep = 1;
                adev->bulkinep = 1;
                for (i = 0; i < numep; i++) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
                        ep = usbdev->ep_in[i];
                        if (!ep)
                                continue;
                        epdesc = &ep->desc;
#else
                        epdesc = usb_epnum_to_ep_desc(usbdev, i);
                        if (!epdesc)
                                continue;
#endif
                        if (epdesc->bmAttributes & USB_ENDPOINT_XFER_BULK) {
                                if (epdesc->bEndpointAddress & 0x80)
                                        adev->bulkinep =
                                            epdesc->bEndpointAddress & 0xF;
                                else
                                        adev->bulkoutep =
                                            epdesc->bEndpointAddress & 0xF;
                        }
                }
        }
        log(L_DEBUG, "bulkout ep: 0x%X\n", adev->bulkoutep);
        log(L_DEBUG, "bulkin ep: 0x%X\n", adev->bulkinep);

        /* already done by memset: adev->rxtruncsize = 0; */
        log(L_DEBUG, "TXBUFSIZE=%d RXBUFSIZE=%d\n",
            (int)TXBUFSIZE, (int)RXBUFSIZE);

        /* Allocate the RX/TX containers. */
        adev->usb_tx = kmalloc(sizeof(usb_tx_t) * ACX_TX_URB_CNT, GFP_KERNEL);
        if (!adev->usb_tx) {
                msg = "acx: no memory for tx container";
                goto end_nomem;
        }
        adev->usb_rx = kmalloc(sizeof(usb_rx_t) * ACX_RX_URB_CNT, GFP_KERNEL);
        if (!adev->usb_rx) {
                msg = "acx: no memory for rx container";
                goto end_nomem;
        }

        /* Setup URBs for bulk-in/out messages */
        for (i = 0; i < ACX_RX_URB_CNT; i++) {
                adev->usb_rx[i].urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!adev->usb_rx[i].urb) {
                        msg = "acx: no memory for input URB\n";
                        goto end_nomem;
                }
                adev->usb_rx[i].urb->status = 0;
                adev->usb_rx[i].adev = adev;
                adev->usb_rx[i].busy = 0;
        }

        for (i = 0; i < ACX_TX_URB_CNT; i++) {
                adev->usb_tx[i].urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!adev->usb_tx[i].urb) {
                        msg = "acx: no memory for output URB\n";
                        goto end_nomem;
                }
                adev->usb_tx[i].urb->status = 0;
                adev->usb_tx[i].adev = adev;
                adev->usb_tx[i].busy = 0;
        }
        adev->tx_free = ACX_TX_URB_CNT;

        usb_set_intfdata(intf, adev);
        SET_IEEE80211_DEV(ieee, &intf->dev);

        /* TODO: move all of fw cmds to open()? But then we won't know our MAC addr
           until ifup (it's available via reading ACX1xx_IE_DOT11_STATION_ID)... */

        /* put acx out of sleep mode and initialize it */
        acx_s_issue_cmd(adev, ACX1xx_CMD_WAKE, NULL, 0);

        result = acx_s_init_mac(adev);
        if (result)
                goto end;

        /* TODO: see similar code in pci.c */
        acxusb_s_read_eeprom_version(adev);
        acxusb_s_fill_configoption(adev);
        acx_s_set_defaults(adev);
        acx_s_get_firmware_version(adev);
        acx_display_hardware_details(adev);

/*      MAC_COPY(ndev->dev_addr, adev->dev_addr); */

        /* Register the network device */
        log(L_INIT, "registering network device\n");
        result = ieee80211_register_hw(adev->ieee);
        if (result) {
                msg = "acx: failed to register USB network device "
                    "(error %d)\n";
                goto end_nomem;
        }

        acx_proc_register_entries(ieee);


        printk("acx: USB module " ACX_RELEASE " loaded successfully\n");

        acx_init_task_scheduler(adev);

#if CMD_DISCOVERY
        great_inquisitor(adev);
#endif

        /* Everything went OK, we are happy now */
        result = OK;
        goto end;

      end_nomem:
        printk(msg, result);

        if (ieee) {
                if (adev->usb_rx) {
                        for (i = 0; i < ACX_RX_URB_CNT; i++)
                                usb_free_urb(adev->usb_rx[i].urb);
                        kfree(adev->usb_rx);
                }
                if (adev->usb_tx) {
                        for (i = 0; i < ACX_TX_URB_CNT; i++)
                                usb_free_urb(adev->usb_tx[i].urb);
                        kfree(adev->usb_tx);
                }
                ieee80211_free_hw(ieee);
        }

        result = -ENOMEM;
        goto end;

      end_nodev:
        /* no device we could handle, return error. */
        result = -EIO;

      end:
        FN_EXIT1(result);
        return result;
}


/***********************************************************************
** acxusb_e_disconnect()
**
** This function is invoked whenever the user pulls the plug from the USB
** device or the module is removed from the kernel. In these cases, the
** network devices have to be taken down and all allocated memory has
** to be freed.
*/
void acxusb_e_disconnect(struct usb_interface *intf)
{
        unsigned long flags;
        int i;
        acx_device_t *adev = usb_get_intfdata(intf);

        FN_ENTER;

        /* No WLAN device... no sense */
        if (!adev)
                goto end;

        /* Unregister network device
         *
         * If the interface is up, unregister_netdev() will take
         * care of calling our close() function, which takes
         * care of unlinking the urbs, sending the device to
         * sleep, etc...
         * This can't be called with sem or lock held because
         * _close() will try to grab it as well if it's called,
         * deadlocking the machine.
         */
        acx_proc_unregister_entries(adev->ieee);
        ieee80211_unregister_hw(adev->ieee);

        acx_sem_lock(adev);
        acx_lock(adev, flags);
        /* This device exists no more */
        usb_set_intfdata(intf, NULL);

        /*
         * Here we only free them. _close() took care of
         * unlinking them.
         */
        for (i = 0; i < ACX_RX_URB_CNT; ++i) {
                usb_free_urb(adev->usb_rx[i].urb);
        }
        for (i = 0; i < ACX_TX_URB_CNT; ++i) {
                usb_free_urb(adev->usb_tx[i].urb);
        }

        /* Freeing containers */
        kfree(adev->usb_rx);
        kfree(adev->usb_tx);

        acx_unlock(adev, flags);
        acx_sem_unlock(adev);

        ieee80211_free_hw(adev->ieee);
      end:
        FN_EXIT0;
}

/***********************************************************************
** acxusb_e_open()
** This function is called when the user sets up the network interface.
** It initializes a management timer, sets up the USB card and starts
** the network tx queue and USB receive.
*/
int acxusb_e_open(struct ieee80211_hw *hw)
{
        acx_device_t *adev = ieee2adev(hw);
        unsigned long flags;
        int i;

        FN_ENTER;

        acx_sem_lock(adev);

        /* put the ACX100 out of sleep mode */
//      acx_s_issue_cmd(adev, ACX1xx_CMD_WAKE, NULL, 0);

        init_timer(&adev->mgmt_timer);
        adev->mgmt_timer.function = acx_i_timer;
        adev->mgmt_timer.data = (unsigned long)adev;

        /* acx_s_start needs it */
        SET_BIT(adev->dev_state_mask, ACX_STATE_IFACE_UP);
        acx_s_start(adev);

        /* don't acx_start_queue() here, we need to associate first */

        acx_lock(adev, flags);
        for (i = 0; i < ACX_RX_URB_CNT; i++) {
                adev->usb_rx[i].urb->status = 0;
        }

        acxusb_l_poll_rx(adev, &adev->usb_rx[0]);

        acx_setup_modes(adev);
        ieee80211_start_queues(adev->ieee);
        acx_unlock(adev, flags);

        acx_sem_unlock(adev);

        FN_EXIT0;
        return 0;
}


/***********************************************************************
** acxusb_e_close()
**
** This function stops the network functionality of the interface (invoked
** when the user calls ifconfig <wlan> down). The tx queue is halted and
** the device is marked as down. In case there were any pending USB bulk
** transfers, these are unlinked (asynchronously). The module in-use count
** is also decreased in this function.
*/
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
int acxusb_e_close(struct ieee80211_hw *hw)
#else
static void acxusb_e_close(struct ieee80211_hw *hw)
#endif
{
        acx_device_t *adev = ieee2adev(hw);
        unsigned long flags;
        int i;

        FN_ENTER;

            acx_sem_lock(adev);
        if (adev->dev_state_mask & ACX_STATE_IFACE_UP)
        {
//              acxusb_e_down(adev);
                CLEAR_BIT(adev->dev_state_mask, ACX_STATE_IFACE_UP);
        }

/* Code below is remarkably similar to acxpci_s_down(). Maybe we can merge them? */

        acx_free_modes(adev);

        /* Make sure we don't get any more rx requests */
        acx_s_issue_cmd(adev, ACX1xx_CMD_DISABLE_RX, NULL, 0);
        acx_s_issue_cmd(adev, ACX1xx_CMD_DISABLE_TX, NULL, 0);

        /*
         * We must do FLUSH *without* holding sem to avoid a deadlock.
         * See pci.c:acxpci_s_down() for deails.
         */
        acx_sem_unlock(adev);
        flush_scheduled_work();
        acx_sem_lock(adev);

        /* Power down the device */
        acx_s_issue_cmd(adev, ACX1xx_CMD_SLEEP, NULL, 0);

        /* Stop the transmit queue, mark the device as DOWN */
        acx_lock(adev, flags);
//      acx_stop_queue(ndev, "on ifdown");
//      acx_set_status(adev, ACX_STATUS_0_STOPPED);
        /* stop pending rx/tx urb transfers */
        for (i = 0; i < ACX_TX_URB_CNT; i++) {
                acxusb_unlink_urb(adev->usb_tx[i].urb);
                adev->usb_tx[i].busy = 0;
        }
        for (i = 0; i < ACX_RX_URB_CNT; i++) {
                acxusb_unlink_urb(adev->usb_rx[i].urb);
                adev->usb_rx[i].busy = 0;
        }
        adev->tx_free = ACX_TX_URB_CNT;
        acx_unlock(adev, flags);

        /* Must do this outside of lock */
        del_timer_sync(&adev->mgmt_timer);

        acx_sem_unlock(adev);

        FN_EXIT0;
        #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
        return 0;
        #endif
}


/***********************************************************************
** acxusb_l_poll_rx
** This function (re)initiates a bulk-in USB transfer on a given urb
*/
void acxusb_l_poll_rx(acx_device_t * adev, usb_rx_t * rx)
{
        struct usb_device *usbdev;
        struct urb *rxurb;
        int errcode, rxnum;
        unsigned int inpipe;

        FN_ENTER;

        rxurb = rx->urb;
        usbdev = adev->usbdev;

        rxnum = rx - adev->usb_rx;

        inpipe = usb_rcvbulkpipe(usbdev, adev->bulkinep);
        if (unlikely(rxurb->status == -EINPROGRESS)) {
                printk(KERN_ERR
                       "acx: error, rx triggered while rx urb in progress\n");
                /* FIXME: this is nasty, receive is being cancelled by this code
                 * on the other hand, this should not happen anyway...
                 */
                usb_unlink_urb(rxurb);
        } else if (unlikely(rxurb->status == -ECONNRESET)) {
                log(L_USBRXTX, "acx_usb: _poll_rx: connection reset\n");
                goto end;
        }
        rxurb->actual_length = 0;
        usb_fill_bulk_urb(rxurb, usbdev, inpipe, &rx->bulkin,   /* dataptr */
                          RXBUFSIZE,    /* size */
                          acxusb_i_complete_rx, /* handler */
                          rx    /* handler param */
            );
        rxurb->transfer_flags = URB_ASYNC_UNLINK;

        /* ATOMIC: we may be called from complete_rx() usb callback */
        errcode = usb_submit_urb(rxurb, GFP_ATOMIC);
        /* FIXME: evaluate the error code! */
        log(L_USBRXTX, "SUBMIT RX (%d) inpipe=0x%X size=%d errcode=%d\n",
            rxnum, inpipe, (int)RXBUFSIZE, errcode);
      end:
        FN_EXIT0;
}


/***********************************************************************
** acxusb_i_complete_rx()
** Inputs:
**     urb -> pointer to USB request block
**    regs -> pointer to register-buffer for syscalls (see asm/ptrace.h)
**
** This function is invoked by USB subsystem whenever a bulk receive
** request returns.
** The received data is then committed to the network stack and the next
** USB receive is triggered.
*/
void acxusb_i_complete_rx(struct urb *urb)
{
        acx_device_t *adev;
        rxbuffer_t *ptr;
        rxbuffer_t *inbuf;
        usb_rx_t *rx;
        unsigned long flags;
        int size, remsize, packetsize, rxnum;

        FN_ENTER;

        BUG_ON(!urb->context);

        rx = (usb_rx_t *) urb->context;
        adev = rx->adev;

        acx_lock(adev, flags);

        /*
         * Happens on disconnect or close. Don't play with the urb.
         * Don't resubmit it. It will get unlinked by close()
         */
        if (unlikely(!(adev->dev_state_mask & ACX_STATE_IFACE_UP))) {
                log(L_USBRXTX, "rx: device is down, not doing anything\n");
                goto end_unlock;
        }

        inbuf = &rx->bulkin;
        size = urb->actual_length;
        remsize = size;
        rxnum = rx - adev->usb_rx;

        log(L_USBRXTX, "RETURN RX (%d) status=%d size=%d\n",
            rxnum, urb->status, size);

        /* Send the URB that's waiting. */
        log(L_USBRXTX, "rxnum=%d, sending=%d\n", rxnum, rxnum ^ 1);
        acxusb_l_poll_rx(adev, &adev->usb_rx[rxnum ^ 1]);

        if (unlikely(size > sizeof(rxbuffer_t)))
                printk("acx_usb: rx too large: %d, please report\n", size);

        /* check if the transfer was aborted */
        switch (urb->status) {
        case 0:         /* No error */
                break;
        case -EOVERFLOW:
                printk(KERN_ERR "acx: rx data overrun\n");
                adev->rxtruncsize = 0;  /* Not valid anymore. */
                goto end_unlock;
        case -ECONNRESET:
                adev->rxtruncsize = 0;
                goto end_unlock;
        case -ESHUTDOWN:        /* rmmod */
                adev->rxtruncsize = 0;
                goto end_unlock;
        default:
                adev->rxtruncsize = 0;
                adev->stats.rx_errors++;
                printk("acx: rx error (urb status=%d)\n", urb->status);
                goto end_unlock;
        }

        if (unlikely(!size))
                printk("acx: warning, encountered zerolength rx packet\n");

        if (urb->transfer_buffer != inbuf)
                goto end_unlock;

        /* check if previous frame was truncated
         ** FIXME: this code can only handle truncation
         ** of consecutive packets!
         */
        ptr = inbuf;
        if (adev->rxtruncsize) {
                int tail_size;

                ptr = &adev->rxtruncbuf;
                packetsize = RXBUF_BYTES_USED(ptr);
                if (acx_debug & L_USBRXTX) {
                        printk("handling truncated frame (truncsize=%d size=%d "
                               "packetsize(from trunc)=%d)\n",
                               adev->rxtruncsize, size, packetsize);
                        acx_dump_bytes(ptr, RXBUF_HDRSIZE);
                        acx_dump_bytes(inbuf, RXBUF_HDRSIZE);
                }

                /* bytes needed for rxtruncbuf completion: */
                tail_size = packetsize - adev->rxtruncsize;

                if (size < tail_size) {
                        /* there is not enough data to complete this packet,
                         ** simply append the stuff to the truncation buffer
                         */
                        memcpy(((char *)ptr) + adev->rxtruncsize, inbuf, size);
                        adev->rxtruncsize += size;
                        remsize = 0;
                } else {
                        /* ok, this data completes the previously
                         ** truncated packet. copy it into a descriptor
                         ** and give it to the rest of the stack        */

                        /* append tail to previously truncated part
                         ** NB: adev->rxtruncbuf (pointed to by ptr) can't
                         ** overflow because this is already checked before
                         ** truncation buffer was filled. See below,
                         ** "if (packetsize > sizeof(rxbuffer_t))..." code */
                        memcpy(((char *)ptr) + adev->rxtruncsize, inbuf,
                               tail_size);

                        if (acx_debug & L_USBRXTX) {
                                printk("full trailing packet + 12 bytes:\n");
                                acx_dump_bytes(inbuf,
                                               tail_size + RXBUF_HDRSIZE);
                        }
                        acx_l_process_rxbuf(adev, ptr);
                        adev->rxtruncsize = 0;
                        ptr = (rxbuffer_t *) (((char *)inbuf) + tail_size);
                        remsize -= tail_size;
                }
                log(L_USBRXTX, "post-merge size=%d remsize=%d\n",
                    size, remsize);
        }

        /* size = USB data block size
         ** remsize = unprocessed USB bytes left
         ** ptr = current pos in USB data block
         */
        while (remsize) {
                if (remsize < RXBUF_HDRSIZE) {
                        printk("acx: truncated rx header (%d bytes)!\n",
                               remsize);
                        if (ACX_DEBUG)
                                acx_dump_bytes(ptr, remsize);
                        break;
                }

                packetsize = RXBUF_BYTES_USED(ptr);
                log(L_USBRXTX, "packet with packetsize=%d\n", packetsize);

                if (RXBUF_IS_TXSTAT(ptr)) {
                        /* do rate handling */
                        usb_txstatus_t *stat = (void *)ptr;

                        log(L_USBRXTX, "tx: stat: mac_cnt_rcvd:%04X "
                            "queue_index:%02X mac_status:%02X hostdata:%08X "
                            "rate:%u ack_failures:%02X rts_failures:%02X "
                            "rts_ok:%02X\n",
                            stat->mac_cnt_rcvd,
                            stat->queue_index, stat->mac_status, stat->hostdata,
                            stat->rate, stat->ack_failures, stat->rts_failures,
                            stat->rts_ok);
/*
                        if (adev->rate_auto && client_no < VEC_SIZE(adev->sta_list)) {
                                client_t *clt = &adev->sta_list[client_no];
                                u16 cur = stat->hostdata >> 16;

                                if (clt && clt->rate_cur == cur) {
                                        acx_l_handle_txrate_auto(adev, clt,
                                                cur, // intended rate 
                                                stat->rate, 0, // actually used rate 
                                                stat->mac_status, // error? 
                                                ACX_TX_URB_CNT - adev->tx_free);
                                }
                        }
*/ goto next;
                }

                if (packetsize > sizeof(rxbuffer_t)) {
                        printk("acx: packet exceeds max wlan "
                               "frame size (%d > %d). size=%d\n",
                               packetsize, (int)sizeof(rxbuffer_t), size);
                        if (ACX_DEBUG)
                                acx_dump_bytes(ptr, 16);
                        /* FIXME: put some real error-handling in here! */
                        break;
                }

                if (packetsize > remsize) {
                        /* frame truncation handling */
                        if (acx_debug & L_USBRXTX) {
                                printk("need to truncate packet, "
                                       "packetsize=%d remsize=%d "
                                       "size=%d bytes:",
                                       packetsize, remsize, size);
                                acx_dump_bytes(ptr, RXBUF_HDRSIZE);
                        }
                        memcpy(&adev->rxtruncbuf, ptr, remsize);
                        adev->rxtruncsize = remsize;
                        break;
                }

                /* packetsize <= remsize */
                /* now handle the received data */
                acx_l_process_rxbuf(adev, ptr);
              next:
                ptr = (rxbuffer_t *) (((char *)ptr) + packetsize);
                remsize -= packetsize;
                if ((acx_debug & L_USBRXTX) && remsize) {
                        printk("more than one packet in buffer, "
                               "second packet hdr:");
                        acx_dump_bytes(ptr, RXBUF_HDRSIZE);
                }
        }

      end_unlock:
        acx_unlock(adev, flags);
/* end: */
        FN_EXIT0;
}


/***********************************************************************
** acxusb_i_complete_tx()
** Inputs:
**     urb -> pointer to USB request block
**    regs -> pointer to register-buffer for syscalls (see asm/ptrace.h)
**
** This function is invoked upon termination of a USB transfer.
*/
void acxusb_i_complete_tx(struct urb *urb)
{
        acx_device_t *adev;
        usb_tx_t *tx;
        unsigned long flags;
        int txnum;

        FN_ENTER;

        BUG_ON(!urb->context);

        tx = (usb_tx_t *) urb->context;
        adev = tx->adev;

        txnum = tx - adev->usb_tx;

        acx_lock(adev, flags);

        /*
         * If the iface isn't up, we don't have any right
         * to play with them. The urb may get unlinked.
         */
        if (unlikely(!(adev->dev_state_mask & ACX_STATE_IFACE_UP))) {
                log(L_USBRXTX, "tx: device is down, not doing anything\n");
                goto end_unlock;
        }

        log(L_USBRXTX, "RETURN TX (%d): status=%d size=%d\n",
            txnum, urb->status, urb->actual_length);

        /* handle USB transfer errors */
        switch (urb->status) {
        case 0:         /* No error */
                break;
        case -ESHUTDOWN:
                goto end_unlock;
                break;
        case -ECONNRESET:
                goto end_unlock;
                break;
                /* FIXME: real error-handling code here please */
        default:
                printk(KERN_ERR "acx: tx error, urb status=%d\n", urb->status);
                /* FIXME: real error-handling code here please */
        }

        /* free the URB and check for more data */
        tx->busy = 0;
        adev->tx_free++;
        if ((adev->tx_free >= TX_START_QUEUE)
            && (adev->status == ACX_STATUS_4_ASSOCIATED)
/*          && (acx_queue_stopped(adev->ndev)*/) {
                log(L_BUF, "tx: wake queue (%u free txbufs)\n", adev->tx_free);
/*              acx_wake_queue(adev->ndev, NULL); */
        }

      end_unlock:
        acx_unlock(adev, flags);
/* end: */
        FN_EXIT0;
}


/***************************************************************
** acxusb_l_alloc_tx
** Actually returns a usb_tx_t* ptr
*/
tx_t *acxusb_l_alloc_tx(acx_device_t * adev)
{
        usb_tx_t *tx;
        unsigned head;

        FN_ENTER;

        head = adev->tx_head;
        do {
                head = (head + 1) % ACX_TX_URB_CNT;
                if (!adev->usb_tx[head].busy) {
                        log(L_USBRXTX, "allocated tx %d\n", head);
                        tx = &adev->usb_tx[head];
                        tx->busy = 1;
                        adev->tx_free--;
                        /* Keep a few free descs between head and tail of tx ring.
                         ** It is not absolutely needed, just feels safer */
                        if (adev->tx_free < TX_STOP_QUEUE) {
                                log(L_BUF, "tx: stop queue "
                                    "(%u free txbufs)\n", adev->tx_free);
/*                              acx_stop_queue(adev->ndev, NULL); */
                        }
                        goto end;
                }
        } while (likely(head != adev->tx_head));
        tx = NULL;
        printk_ratelimited("acx: tx buffers full\n");
      end:
        adev->tx_head = head;
        FN_EXIT0;
        return (tx_t *) tx;
}


/***************************************************************
** Used if alloc_tx()'ed buffer needs to be cancelled without doing tx
*/
void acxusb_l_dealloc_tx(tx_t * tx_opaque)
{
        usb_tx_t *tx = (usb_tx_t *) tx_opaque;
        tx->busy = 0;
}


/***************************************************************
*/
void *acxusb_l_get_txbuf(acx_device_t * adev, tx_t * tx_opaque)
{
        usb_tx_t *tx = (usb_tx_t *) tx_opaque;
        return &tx->bulkout.data;
}


/***************************************************************
** acxusb_l_tx_data
**
** Can be called from IRQ (rx -> (AP bridging or mgmt response) -> tx).
** Can be called from acx_i_start_xmit (data frames from net core).
*/
void acxusb_l_tx_data(acx_device_t * adev, tx_t * tx_opaque, int wlanpkt_len, struct ieee80211_tx_control *ctl,
                                struct sk_buff* skb)
{
        struct usb_device *usbdev;
        struct urb *txurb;
        usb_tx_t *tx;
        usb_txbuffer_t *txbuf;
//      client_t *clt;
        struct ieee80211_hdr *whdr;
        unsigned int outpipe;
        int ucode, txnum;

        FN_ENTER;

        tx = ((usb_tx_t *) tx_opaque);
        txurb = tx->urb;
        txbuf = &tx->bulkout;
        whdr = (struct ieee80211_hdr *) txbuf->data;
        txnum = tx - adev->usb_tx;

        log(L_DEBUG, "using buf#%d free=%d len=%d\n",
            txnum, adev->tx_free, wlanpkt_len);
/*
        switch (adev->mode) {
        case ACX_MODE_0_ADHOC:
        case ACX_MODE_3_AP:
                clt = acx_l_sta_list_get(adev, whdr->a1);
                break;
        case ACX_MODE_2_STA:
//              clt = adev->ap_client;
                break;
        default:
                clt = NULL;
                break;
        }
        if (unlikely(clt && !clt->rate_cur)) {
                printk("acx: driver bug! bad ratemask\n");
                goto end;
        }
*/

        /* fill the USB transfer header */
        txbuf->desc = cpu_to_le16(USB_TXBUF_TXDESC);
        txbuf->mpdu_len = cpu_to_le16(wlanpkt_len);
        txbuf->queue_index = 1;
        txbuf->rate = ctl->tx_rate; //clt->rate_100;
//              FIXME();        //This used to have | (clt - adev->ap_client)
        txbuf->hostdata = (ctl->tx_rate << 16);
        txbuf->ctrl1 = DESC_CTL_FIRSTFRAG;
        if (1 == adev->preamble_cur)
                SET_BIT(txbuf->ctrl1, DESC_CTL_SHORT_PREAMBLE);
        txbuf->ctrl2 = 0;
        txbuf->data_len = cpu_to_le16(wlanpkt_len);

        if (unlikely(acx_debug & L_DATA)) {
                printk("dump of bulk out urb:\n");
                acx_dump_bytes(txbuf, wlanpkt_len + USB_TXBUF_HDRSIZE);
        }

        if (unlikely(txurb->status == -EINPROGRESS)) {
                printk
                    ("acx: trying to submit tx urb while already in progress\n");
        }

        /* now schedule the USB transfer */
        usbdev = adev->usbdev;
        outpipe = usb_sndbulkpipe(usbdev, adev->bulkoutep);

        usb_fill_bulk_urb(txurb, usbdev, outpipe, txbuf,        /* dataptr */
                          wlanpkt_len + USB_TXBUF_HDRSIZE,      /* size */
                          acxusb_i_complete_tx, /* handler */
                          tx    /* handler param */
            );

        txurb->transfer_flags = URB_ASYNC_UNLINK | URB_ZERO_PACKET;
        ucode = usb_submit_urb(txurb, GFP_ATOMIC);
        log(L_USBRXTX, "SUBMIT TX (%d): outpipe=0x%X buf=%p txsize=%d "
            "rate=%u errcode=%d\n", txnum, outpipe, txbuf,
            wlanpkt_len + USB_TXBUF_HDRSIZE, txbuf->rate, ucode);

        if (unlikely(ucode)) {
                printk(KERN_ERR "acx: submit_urb() error=%d txsize=%d\n",
                       ucode, wlanpkt_len + USB_TXBUF_HDRSIZE);

                /* on error, just mark the frame as done and update
                 ** the statistics
                 */
                adev->stats.tx_errors++;
                tx->busy = 0;
                adev->tx_free++;
                /* needed? if (adev->tx_free > TX_START_QUEUE) acx_wake_queue(...) */
        }
        FN_EXIT0;
}


/***********************************************************************
static void acxusb_i_set_rx_mode(struct net_device *ndev)
{
}
*/


/***********************************************************************
*/
#ifdef HAVE_TX_TIMEOUT
/*
void acxusb_i_tx_timeout(struct net_device *ndev)
{
        acx_device_t *adev = ndev2adev(ndev);
        unsigned long flags;
        int i;

        FN_ENTER;

        acx_lock(adev, flags);
*/      /* unlink the URBs */
/*      for (i = 0; i < ACX_TX_URB_CNT; i++) {
                acxusb_unlink_urb(adev->usb_tx[i].urb);
                adev->usb_tx[i].busy = 0;
        }
        adev->tx_free = ACX_TX_URB_CNT;
*/      /* TODO: stats update */
/*      acx_unlock(adev, flags);

        FN_EXIT0;
}
*/
#endif


/***********************************************************************
** init_module()
**
** This function is invoked upon loading of the kernel module.
** It registers itself at the kernel's USB subsystem.
**
** Returns: Errorcode on failure, 0 on success
*/
int __init acxusb_e_init_module(void)
{
        log(L_INIT, "USB module " ACX_RELEASE " initialized, "
            "probing for devices...\n");
        return usb_register(&acxusb_driver);
}



/***********************************************************************
** cleanup_module()
**
** This function is invoked as last step of the module unloading. It simply
** deregisters this module at the kernel's USB subsystem.
*/
void __exit acxusb_e_cleanup_module(void)
{
        usb_deregister(&acxusb_driver);
        log(L_INIT, "USB module " ACX_RELEASE " unloaded\n");
}


/***********************************************************************
** DEBUG STUFF
*/
#if ACX_DEBUG

#ifdef UNUSED
static void dump_device(struct usb_device *usbdev)
{
        int i;
        struct usb_config_descriptor *cd;

        printk("acx device dump:\n");
        printk("  devnum: %d\n", usbdev->devnum);
        printk("  speed: %d\n", usbdev->speed);
        printk("  tt: 0x%X\n", (unsigned int)(usbdev->tt));
        printk("  ttport: %d\n", (unsigned int)(usbdev->ttport));
        printk("  toggle[0]: 0x%X  toggle[1]: 0x%X\n",
               (unsigned int)(usbdev->toggle[0]),
               (unsigned int)(usbdev->toggle[1]));
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 11)
        /* This saw a change after 2.6.10 */
        printk("  ep_in wMaxPacketSize: ");
        for (i = 0; i < 16; ++i)
                if (usbdev->ep_in[i] != NULL)
                        printk("%d:%d ", i,
                               usbdev->ep_in[i]->desc.wMaxPacketSize);
        printk("\n");
        printk("  ep_out wMaxPacketSize: ");
        for (i = 0; i < ARRAY_SIZE(usbdev->ep_out); ++i)
                if (usbdev->ep_out[i] != NULL)
                        printk("%d:%d ", i,
                               usbdev->ep_out[i]->desc.wMaxPacketSize);
        printk("\n");
#else
        printk("  epmaxpacketin: ");
        for (i = 0; i < 16; i++)
                printk("%d ", usbdev->epmaxpacketin[i]);
        printk("\n");
        printk("  epmaxpacketout: ");
        for (i = 0; i < 16; i++)
                printk("%d ", usbdev->epmaxpacketout[i]);
        printk("\n");
#endif
        printk("  parent: 0x%X\n", (unsigned int)usbdev->parent);
        printk("  bus: 0x%X\n", (unsigned int)usbdev->bus);
#ifdef NO_DATATYPE
        printk("  configs: ");
        for (i = 0; i < usbdev->descriptor.bNumConfigurations; i++)
                printk("0x%X ", usbdev->config[i]);
        printk("\n");
#endif
        printk("  actconfig: %p\n", usbdev->actconfig);
        dump_device_descriptor(&usbdev->descriptor);

        cd = &usbdev->config->desc;
        dump_config_descriptor(cd);
}


/***********************************************************************
*/
static void dump_config_descriptor(struct usb_config_descriptor *cd)
{
        printk("Configuration Descriptor:\n");
        if (!cd) {
                printk("NULL\n");
                return;
        }
        printk("  bLength: %d (0x%X)\n", cd->bLength, cd->bLength);
        printk("  bDescriptorType: %d (0x%X)\n", cd->bDescriptorType,
               cd->bDescriptorType);
        printk("  bNumInterfaces: %d (0x%X)\n", cd->bNumInterfaces,
               cd->bNumInterfaces);
        printk("  bConfigurationValue: %d (0x%X)\n", cd->bConfigurationValue,
               cd->bConfigurationValue);
        printk("  iConfiguration: %d (0x%X)\n", cd->iConfiguration,
               cd->iConfiguration);
        printk("  bmAttributes: %d (0x%X)\n", cd->bmAttributes,
               cd->bmAttributes);
        /* printk("  MaxPower: %d (0x%X)\n", cd->bMaxPower, cd->bMaxPower); */
}


static void dump_device_descriptor(struct usb_device_descriptor *dd)
{
        printk("Device Descriptor:\n");
        if (!dd) {
                printk("NULL\n");
                return;
        }
        printk("  bLength: %d (0x%X)\n", dd->bLength, dd->bLength);
        printk("  bDescriptortype: %d (0x%X)\n", dd->bDescriptorType,
               dd->bDescriptorType);
        printk("  bcdUSB: %d (0x%X)\n", dd->bcdUSB, dd->bcdUSB);
        printk("  bDeviceClass: %d (0x%X)\n", dd->bDeviceClass,
               dd->bDeviceClass);
        printk("  bDeviceSubClass: %d (0x%X)\n", dd->bDeviceSubClass,
               dd->bDeviceSubClass);
        printk("  bDeviceProtocol: %d (0x%X)\n", dd->bDeviceProtocol,
               dd->bDeviceProtocol);
        printk("  bMaxPacketSize0: %d (0x%X)\n", dd->bMaxPacketSize0,
               dd->bMaxPacketSize0);
        printk("  idVendor: %d (0x%X)\n", dd->idVendor, dd->idVendor);
        printk("  idProduct: %d (0x%X)\n", dd->idProduct, dd->idProduct);
        printk("  bcdDevice: %d (0x%X)\n", dd->bcdDevice, dd->bcdDevice);
        printk("  iManufacturer: %d (0x%X)\n", dd->iManufacturer,
               dd->iManufacturer);
        printk("  iProduct: %d (0x%X)\n", dd->iProduct, dd->iProduct);
        printk("  iSerialNumber: %d (0x%X)\n", dd->iSerialNumber,
               dd->iSerialNumber);
        printk("  bNumConfigurations: %d (0x%X)\n", dd->bNumConfigurations,
               dd->bNumConfigurations);
}
#endif /* UNUSED */

#endif /* ACX_DEBUG */