patch-2.4.22 linux-2.4.22/drivers/usb/speedtch.c

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diff -urN linux-2.4.21/drivers/usb/speedtch.c linux-2.4.22/drivers/usb/speedtch.c
@@ -0,0 +1,1344 @@
+/******************************************************************************
+ *  speedtouch.c  -  Alcatel SpeedTouch USB xDSL modem driver
+ *
+ *  Copyright (C) 2001, Alcatel
+ *  Copyright (C) 2003, Duncan Sands
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the Free
+ *  Software Foundation; either version 2 of the License, or (at your option)
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ *  more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with
+ *  this program; if not, write to the Free Software Foundation, Inc., 59
+ *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ ******************************************************************************/
+
+/*
+ *  Written by Johan Verrept, maintained by Duncan Sands (duncan.sands@wanadoo.fr)
+ *
+ *  1.6:	- No longer opens a connection if the firmware is not loaded
+ *  		- Added support for the speedtouch 330
+ *  		- Removed the limit on the number of devices
+ *  		- Module now autoloads on device plugin
+ *  		- Merged relevant parts of sarlib
+ *  		- Replaced the kernel thread with a tasklet
+ *  		- New packet transmission code
+ *  		- Changed proc file contents
+ *  		- Fixed all known SMP races
+ *  		- Many fixes and cleanups
+ *  		- Various fixes by Oliver Neukum (oliver@neukum.name)
+ *
+ *  1.5A:	- Backport of version for inclusion in 2.5 series kernel
+ *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
+ *		- made compatible with kernel 2.5.6 onwards by changing
+ *		udsl_usb_send_data_context->urb to a pointer and adding code
+ *		to alloc and free it
+ *		- remove_wait_queue() added to udsl_atm_processqueue_thread()
+ *
+ *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
+ *		(reported by stephen.robinson@zen.co.uk)
+ *
+ *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
+ *		- unlink all active send urbs of a vcc that is being closed.
+ *
+ *  1.3.1:	- added the version number
+ *
+ *  1.3:	- Added multiple send urb support
+ *		- fixed memory leak and vcc->tx_inuse starvation bug
+ *		  when not enough memory left in vcc.
+ *
+ *  1.2:	- Fixed race condition in udsl_usb_send_data()
+ *  1.1:	- Turned off packet debugging
+ *
+ */
+
+#include <asm/semaphore.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/errno.h>
+#include <linux/proc_fs.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <asm/uaccess.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/crc32.h>
+#include <linux/init.h>
+
+/*
+#define DEBUG
+#define VERBOSE_DEBUG
+*/
+
+#include <linux/usb.h>
+
+
+#ifdef VERBOSE_DEBUG
+static int udsl_print_packet (const unsigned char *data, int len);
+#define PACKETDEBUG(arg...)	udsl_print_packet (arg)
+#define vdbg(arg...)		dbg (arg)
+#else
+#define PACKETDEBUG(arg...)
+#define vdbg(arg...)
+#endif
+
+#define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@wanadoo.fr>"
+#define DRIVER_DESC	"Alcatel SpeedTouch USB driver"
+#define DRIVER_VERSION	"1.6"
+
+static const char udsl_driver_name [] = "speedtch";
+
+#define SPEEDTOUCH_VENDORID		0x06b9
+#define SPEEDTOUCH_PRODUCTID		0x4061
+
+#define UDSL_MAX_RCV_URBS		4
+#define UDSL_MAX_SND_URBS		4
+#define UDSL_MAX_RCV_BUFS		8
+#define UDSL_MAX_SND_BUFS		8
+#define UDSL_MAX_RCV_BUF_SIZE		1024 /* ATM cells */
+#define UDSL_MAX_SND_BUF_SIZE		1024 /* ATM cells */
+#define UDSL_DEFAULT_RCV_URBS		1
+#define UDSL_DEFAULT_SND_URBS		1
+#define UDSL_DEFAULT_RCV_BUFS		2
+#define UDSL_DEFAULT_SND_BUFS		2
+#define UDSL_DEFAULT_RCV_BUF_SIZE	64 /* ATM cells */
+#define UDSL_DEFAULT_SND_BUF_SIZE	64 /* ATM cells */
+
+static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
+static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
+static unsigned int num_rcv_bufs = UDSL_DEFAULT_RCV_BUFS;
+static unsigned int num_snd_bufs = UDSL_DEFAULT_SND_BUFS;
+static unsigned int rcv_buf_size = UDSL_DEFAULT_RCV_BUF_SIZE;
+static unsigned int snd_buf_size = UDSL_DEFAULT_SND_BUF_SIZE;
+
+MODULE_PARM (num_rcv_urbs, "i");
+MODULE_PARM_DESC (num_rcv_urbs, "Number of urbs used for reception (range: 0-" __MODULE_STRING (UDSL_MAX_RCV_URBS) ", default: " __MODULE_STRING (UDSL_DEFAULT_RCV_URBS) ")");
+
+MODULE_PARM (num_snd_urbs, "i");
+MODULE_PARM_DESC (num_snd_urbs, "Number of urbs used for transmission (range: 0-" __MODULE_STRING (UDSL_MAX_SND_URBS) ", default: " __MODULE_STRING (UDSL_DEFAULT_SND_URBS) ")");
+
+MODULE_PARM (num_rcv_bufs, "i");
+MODULE_PARM_DESC (num_rcv_bufs, "Number of buffers used for reception (range: 0-" __MODULE_STRING (UDSL_MAX_RCV_BUFS) ", default: " __MODULE_STRING (UDSL_DEFAULT_RCV_BUFS) ")");
+
+MODULE_PARM (num_snd_bufs, "i");
+MODULE_PARM_DESC (num_snd_bufs, "Number of buffers used for transmission (range: 0-" __MODULE_STRING (UDSL_MAX_SND_BUFS) ", default: " __MODULE_STRING (UDSL_DEFAULT_SND_BUFS) ")");
+
+MODULE_PARM (rcv_buf_size, "i");
+MODULE_PARM_DESC (rcv_buf_size, "Size of the buffers used for reception (range: 0-" __MODULE_STRING (UDSL_MAX_RCV_BUF_SIZE) ", default: " __MODULE_STRING (UDSL_DEFAULT_RCV_BUF_SIZE) ")");
+
+MODULE_PARM (snd_buf_size, "i");
+MODULE_PARM_DESC (snd_buf_size, "Size of the buffers used for transmission (range: 0-" __MODULE_STRING (UDSL_MAX_SND_BUF_SIZE) ", default: " __MODULE_STRING (UDSL_DEFAULT_SND_BUF_SIZE) ")");
+
+#define UDSL_IOCTL_LINE_UP		1
+#define UDSL_IOCTL_LINE_DOWN		2
+
+#define UDSL_ENDPOINT_DATA_OUT		0x07
+#define UDSL_ENDPOINT_DATA_IN		0x87
+
+#define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
+#define UDSL_NUM_CELLS(x)		(((x) + ATM_AAL5_TRAILER + ATM_CELL_PAYLOAD - 1) / ATM_CELL_PAYLOAD)
+
+#define hex2int(c) ( (c >= '0') && (c <= '9') ? (c - '0') : ((c & 0xf) + 9) )
+
+static struct usb_device_id udsl_usb_ids [] = {
+	{ USB_DEVICE (SPEEDTOUCH_VENDORID, SPEEDTOUCH_PRODUCTID) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE (usb, udsl_usb_ids);
+
+/* receive */
+
+struct udsl_receive_buffer {
+	struct list_head list;
+	unsigned char *base;
+	unsigned int filled_cells;
+};
+
+struct udsl_receiver {
+	struct list_head list;
+	struct udsl_receive_buffer *buffer;
+	struct urb *urb;
+	struct udsl_instance_data *instance;
+};
+
+struct udsl_vcc_data {
+	/* vpi/vci lookup */
+	struct list_head list;
+	short vpi;
+	int vci;
+	struct atm_vcc *vcc;
+
+	/* raw cell reassembly */
+	struct sk_buff *skb;
+	unsigned int max_pdu;
+};
+
+/* send */
+
+struct udsl_send_buffer {
+	struct list_head list;
+	unsigned char *base;
+	unsigned char *free_start;
+	unsigned int free_cells;
+};
+
+struct udsl_sender {
+	struct list_head list;
+	struct udsl_send_buffer *buffer;
+	struct urb *urb;
+	struct udsl_instance_data *instance;
+};
+
+struct udsl_control {
+	struct atm_skb_data atm_data;
+	unsigned int num_cells;
+	unsigned int num_entire;
+	unsigned int pdu_padding;
+	unsigned char cell_header [ATM_CELL_HEADER];
+	unsigned char aal5_trailer [ATM_AAL5_TRAILER];
+};
+
+#define UDSL_SKB(x)		((struct udsl_control *)(x)->cb)
+
+/* main driver data */
+
+struct udsl_instance_data {
+	struct semaphore serialize;
+
+	/* USB device part */
+	struct usb_device *usb_dev;
+	char description [64];
+	int firmware_loaded;
+
+	/* ATM device part */
+	struct atm_dev *atm_dev;
+	struct list_head vcc_list;
+
+	/* receive */
+	struct udsl_receiver receivers [UDSL_MAX_RCV_URBS];
+	struct udsl_receive_buffer receive_buffers [UDSL_MAX_RCV_BUFS];
+
+	spinlock_t receive_lock;
+	struct list_head spare_receivers;
+	struct list_head filled_receive_buffers;
+
+	struct tasklet_struct receive_tasklet;
+	struct list_head spare_receive_buffers;
+
+	/* send */
+	struct udsl_sender senders [UDSL_MAX_SND_URBS];
+	struct udsl_send_buffer send_buffers [UDSL_MAX_SND_BUFS];
+
+	struct sk_buff_head sndqueue;
+
+	spinlock_t send_lock;
+	struct list_head spare_senders;
+	struct list_head spare_send_buffers;
+
+	struct tasklet_struct send_tasklet;
+	struct sk_buff *current_skb;			/* being emptied */
+	struct udsl_send_buffer *current_buffer;	/* being filled */
+	struct list_head filled_send_buffers;
+};
+
+/* ATM */
+
+static void udsl_atm_dev_close (struct atm_dev *dev);
+static int udsl_atm_open (struct atm_vcc *vcc, short vpi, int vci);
+static void udsl_atm_close (struct atm_vcc *vcc);
+static int udsl_atm_ioctl (struct atm_dev *dev, unsigned int cmd, void *arg);
+static int udsl_atm_send (struct atm_vcc *vcc, struct sk_buff *skb);
+static int udsl_atm_proc_read (struct atm_dev *atm_dev, loff_t *pos, char *page);
+
+static struct atmdev_ops udsl_atm_devops = {
+	dev_close:	udsl_atm_dev_close,
+	open:		udsl_atm_open,
+	close:		udsl_atm_close,
+	ioctl:		udsl_atm_ioctl,
+	send:		udsl_atm_send,
+	proc_read:	udsl_atm_proc_read,
+	owner:		THIS_MODULE,
+};
+
+/* USB */
+
+static void *udsl_usb_probe (struct usb_device *dev, unsigned int ifnum, const struct usb_device_id *id);
+static void udsl_usb_disconnect (struct usb_device *dev, void *ptr);
+static int udsl_usb_ioctl (struct usb_device *hub, unsigned int code, void *user_data);
+
+static struct usb_driver udsl_usb_driver = {
+	owner:		THIS_MODULE,
+	name:		udsl_driver_name,
+	probe:		udsl_usb_probe,
+	disconnect:	udsl_usb_disconnect,
+	ioctl:		udsl_usb_ioctl,
+	id_table:	udsl_usb_ids,
+};
+
+
+/*************
+**  decode  **
+*************/
+
+static inline struct udsl_vcc_data *udsl_find_vcc (struct udsl_instance_data *instance, short vpi, int vci)
+{
+	struct udsl_vcc_data *vcc;
+
+	list_for_each_entry (vcc, &instance->vcc_list, list)
+		if ((vcc->vci == vci) && (vcc->vpi == vpi))
+			return vcc;
+	return NULL;
+}
+
+static void udsl_extract_cells (struct udsl_instance_data *instance, unsigned char *source, unsigned int howmany)
+{
+	struct udsl_vcc_data *cached_vcc = NULL;
+	struct atm_vcc *vcc;
+	struct sk_buff *skb;
+	struct udsl_vcc_data *vcc_data;
+	int cached_vci = 0;
+	unsigned int i;
+	unsigned int length;
+	unsigned int pdu_length;
+	int pti;
+	int vci;
+	short cached_vpi = 0;
+	short vpi;
+
+	for (i = 0; i < howmany; i++, source += ATM_CELL_SIZE) {
+		vpi = ((source [0] & 0x0f) << 4) | (source [1] >> 4);
+		vci = ((source [1] & 0x0f) << 12) | (source [2] << 4) | (source [3] >> 4);
+		pti = (source [3] & 0x2) != 0;
+
+		vdbg ("udsl_extract_cells: vpi %hd, vci %d, pti %d", vpi, vci, pti);
+
+		if (cached_vcc && (vci == cached_vci) && (vpi == cached_vpi))
+			vcc_data = cached_vcc;
+		else if ((vcc_data = udsl_find_vcc (instance, vpi, vci))) {
+			cached_vcc = vcc_data;
+			cached_vpi = vpi;
+			cached_vci = vci;
+		} else {
+			dbg ("udsl_extract_cells: unknown vpi/vci (%hd/%d)!", vpi, vci);
+			continue;
+		}
+
+		vcc = vcc_data->vcc;
+
+		if (!vcc_data->skb && !(vcc_data->skb = dev_alloc_skb (vcc_data->max_pdu))) {
+			dbg ("udsl_extract_cells: no memory for skb (vcc: 0x%p)!", vcc);
+			if (pti)
+				atomic_inc (&vcc->stats->rx_err);
+			continue;
+		}
+
+		skb = vcc_data->skb;
+
+		if (skb->len + ATM_CELL_PAYLOAD > vcc_data->max_pdu) {
+			dbg ("udsl_extract_cells: buffer overrun (max_pdu: %u, skb->len %u, vcc: 0x%p)", vcc_data->max_pdu, skb->len, vcc);
+			/* discard cells already received */
+			skb_trim (skb, 0);
+			BUG_ON (vcc_data->max_pdu < ATM_CELL_PAYLOAD);
+		}
+
+		memcpy (skb->tail, source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
+		__skb_put (skb, ATM_CELL_PAYLOAD);
+
+		if (pti) {
+			length = (source [ATM_CELL_SIZE - 6] << 8) + source [ATM_CELL_SIZE - 5];
+
+			/* guard against overflow */
+			if (length > ATM_MAX_AAL5_PDU) {
+				dbg ("udsl_extract_cells: bogus length %u (vcc: 0x%p)", length, vcc);
+				goto drop;
+			}
+
+			pdu_length = UDSL_NUM_CELLS (length) * ATM_CELL_PAYLOAD;
+
+			if (skb->len < pdu_length) {
+				dbg ("udsl_extract_cells: bogus pdu_length %u (skb->len: %u, vcc: 0x%p)", pdu_length, skb->len, vcc);
+				goto drop;
+			}
+
+			if (crc32_be (~0, skb->tail - pdu_length, pdu_length) != 0xc704dd7b) {
+				dbg ("udsl_extract_cells: packet failed crc check (vcc: 0x%p)", vcc);
+				goto drop;
+			}
+
+			if (!atm_charge (vcc, skb->truesize)) {
+				dbg ("udsl_extract_cells: failed atm_charge (skb->truesize: %u)", skb->truesize);
+				goto drop_no_stats; /* atm_charge increments rx_drop */
+			}
+
+			/* now that we are sure to send the skb, it is ok to change skb->data */
+			if (skb->len > pdu_length)
+				skb_pull (skb, skb->len - pdu_length); /* discard initial junk */
+
+			skb_trim (skb, length); /* drop zero padding and trailer */
+
+			atomic_inc (&vcc->stats->rx);
+
+			PACKETDEBUG (skb->data, skb->len);
+
+			vdbg ("udsl_extract_cells: sending skb 0x%p, skb->len %u, skb->truesize %u", skb, skb->len, skb->truesize);
+
+			vcc->push (vcc, skb);
+
+			vcc_data->skb = NULL;
+
+			continue;
+
+drop:
+			atomic_inc (&vcc->stats->rx_err);
+drop_no_stats:
+			skb_trim (skb, 0);
+		}
+	}
+}
+
+
+/*************
+**  encode  **
+*************/
+
+static const unsigned char zeros [ATM_CELL_PAYLOAD];
+
+static void udsl_groom_skb (struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	struct udsl_control *ctrl = UDSL_SKB (skb);
+	unsigned int zero_padding;
+	u32 crc;
+
+	ctrl->atm_data.vcc = vcc;
+	ctrl->cell_header [0] = vcc->vpi >> 4;
+	ctrl->cell_header [1] = (vcc->vpi << 4) | (vcc->vci >> 12);
+	ctrl->cell_header [2] = vcc->vci >> 4;
+	ctrl->cell_header [3] = vcc->vci << 4;
+	ctrl->cell_header [4] = 0xec;
+
+	ctrl->num_cells = UDSL_NUM_CELLS (skb->len);
+	ctrl->num_entire = skb->len / ATM_CELL_PAYLOAD;
+
+	zero_padding = ctrl->num_cells * ATM_CELL_PAYLOAD - skb->len - ATM_AAL5_TRAILER;
+
+	if (ctrl->num_entire + 1 < ctrl->num_cells)
+		ctrl->pdu_padding = zero_padding - (ATM_CELL_PAYLOAD - ATM_AAL5_TRAILER);
+	else
+		ctrl->pdu_padding = zero_padding;
+
+	ctrl->aal5_trailer [0] = 0; /* UU = 0 */
+	ctrl->aal5_trailer [1] = 0; /* CPI = 0 */
+	ctrl->aal5_trailer [2] = skb->len >> 8;
+	ctrl->aal5_trailer [3] = skb->len;
+
+	crc = crc32_be (~0, skb->data, skb->len);
+	crc = crc32_be (crc, zeros, zero_padding);
+	crc = crc32_be (crc, ctrl->aal5_trailer, 4);
+	crc = ~crc;
+
+	ctrl->aal5_trailer [4] = crc >> 24;
+	ctrl->aal5_trailer [5] = crc >> 16;
+	ctrl->aal5_trailer [6] = crc >> 8;
+	ctrl->aal5_trailer [7] = crc;
+}
+
+static unsigned int udsl_write_cells (unsigned int howmany, struct sk_buff *skb, unsigned char **target_p)
+{
+	struct udsl_control *ctrl = UDSL_SKB (skb);
+	unsigned char *target = *target_p;
+	unsigned int nc, ne, i;
+
+	vdbg ("udsl_write_cells: howmany=%u, skb->len=%d, num_cells=%u, num_entire=%u, pdu_padding=%u", howmany, skb->len, ctrl->num_cells, ctrl->num_entire, ctrl->pdu_padding);
+
+	nc = ctrl->num_cells;
+	ne = min (howmany, ctrl->num_entire);
+
+	for (i = 0; i < ne; i++) {
+		memcpy (target, ctrl->cell_header, ATM_CELL_HEADER);
+		target += ATM_CELL_HEADER;
+		memcpy (target, skb->data, ATM_CELL_PAYLOAD);
+		target += ATM_CELL_PAYLOAD;
+		__skb_pull (skb, ATM_CELL_PAYLOAD);
+	}
+
+	ctrl->num_entire -= ne;
+
+	if (!(ctrl->num_cells -= ne) || !(howmany -= ne))
+		goto out;
+
+	memcpy (target, ctrl->cell_header, ATM_CELL_HEADER);
+	target += ATM_CELL_HEADER;
+	memcpy (target, skb->data, skb->len);
+	target += skb->len;
+	__skb_pull (skb, skb->len);
+	memset (target, 0, ctrl->pdu_padding);
+	target += ctrl->pdu_padding;
+
+	if (--ctrl->num_cells) {
+		if (!--howmany) {
+			ctrl->pdu_padding = ATM_CELL_PAYLOAD - ATM_AAL5_TRAILER;
+			goto out;
+		}
+
+		memcpy (target, ctrl->cell_header, ATM_CELL_HEADER);
+		target += ATM_CELL_HEADER;
+		memset (target, 0, ATM_CELL_PAYLOAD - ATM_AAL5_TRAILER);
+		target += ATM_CELL_PAYLOAD - ATM_AAL5_TRAILER;
+
+		BUG_ON (--ctrl->num_cells);
+	}
+
+	memcpy (target, ctrl->aal5_trailer, ATM_AAL5_TRAILER);
+	target += ATM_AAL5_TRAILER;
+	/* set pti bit in last cell */
+	*(target + 3 - ATM_CELL_SIZE) |= 0x2;
+
+out:
+	*target_p = target;
+	return nc - ctrl->num_cells;
+}
+
+
+/**************
+**  receive  **
+**************/
+
+static void udsl_complete_receive (struct urb *urb)
+{
+	struct udsl_receive_buffer *buf;
+	struct udsl_instance_data *instance;
+	struct udsl_receiver *rcv;
+	unsigned long flags;
+
+	if (!urb || !(rcv = urb->context)) {
+		dbg ("udsl_complete_receive: bad urb!");
+		return;
+	}
+
+	instance = rcv->instance;
+	buf = rcv->buffer;
+
+	buf->filled_cells = urb->actual_length / ATM_CELL_SIZE;
+
+	vdbg ("udsl_complete_receive: urb 0x%p, status %d, actual_length %d, filled_cells %u, rcv 0x%p, buf 0x%p", urb, urb->status, urb->actual_length, buf->filled_cells, rcv, buf);
+
+	BUG_ON (buf->filled_cells > rcv_buf_size);
+
+	/* may not be in_interrupt() */
+	spin_lock_irqsave (&instance->receive_lock, flags);
+	list_add (&rcv->list, &instance->spare_receivers);
+	list_add_tail (&buf->list, &instance->filled_receive_buffers);
+	if (likely (!urb->status))
+		tasklet_schedule (&instance->receive_tasklet);
+	spin_unlock_irqrestore (&instance->receive_lock, flags);
+}
+
+static void udsl_process_receive (unsigned long data)
+{
+	struct udsl_receive_buffer *buf;
+	struct udsl_instance_data *instance = (struct udsl_instance_data *) data;
+	struct udsl_receiver *rcv;
+	int err;
+
+made_progress:
+	while (!list_empty (&instance->spare_receive_buffers)) {
+		spin_lock_irq (&instance->receive_lock);
+		if (list_empty (&instance->spare_receivers)) {
+			spin_unlock_irq (&instance->receive_lock);
+			break;
+		}
+		rcv = list_entry (instance->spare_receivers.next, struct udsl_receiver, list);
+		list_del (&rcv->list);
+		spin_unlock_irq (&instance->receive_lock);
+
+		buf = list_entry (instance->spare_receive_buffers.next, struct udsl_receive_buffer, list);
+		list_del (&buf->list);
+
+		rcv->buffer = buf;
+
+		FILL_BULK_URB (rcv->urb,
+			       instance->usb_dev,
+			       usb_rcvbulkpipe (instance->usb_dev, UDSL_ENDPOINT_DATA_IN),
+			       buf->base,
+			       rcv_buf_size * ATM_CELL_SIZE,
+			       udsl_complete_receive,
+			       rcv);
+		rcv->urb->transfer_flags |= USB_QUEUE_BULK;
+
+		vdbg ("udsl_process_receive: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
+
+		if ((err = usb_submit_urb(rcv->urb)) < 0) {
+			dbg ("udsl_process_receive: urb submission failed (%d)!", err);
+			list_add (&buf->list, &instance->spare_receive_buffers);
+			spin_lock_irq (&instance->receive_lock);
+			list_add (&rcv->list, &instance->spare_receivers);
+			spin_unlock_irq (&instance->receive_lock);
+			break;
+		}
+	}
+
+	spin_lock_irq (&instance->receive_lock);
+	if (list_empty (&instance->filled_receive_buffers)) {
+		spin_unlock_irq (&instance->receive_lock);
+		return; /* done - no more buffers */
+	}
+	buf = list_entry (instance->filled_receive_buffers.next, struct udsl_receive_buffer, list);
+	list_del (&buf->list);
+	spin_unlock_irq (&instance->receive_lock);
+	vdbg ("udsl_process_receive: processing buf 0x%p", buf);
+	udsl_extract_cells (instance, buf->base, buf->filled_cells);
+	list_add (&buf->list, &instance->spare_receive_buffers);
+	goto made_progress;
+}
+
+
+/***********
+**  send  **
+***********/
+
+static void udsl_complete_send (struct urb *urb)
+{
+	struct udsl_instance_data *instance;
+	struct udsl_sender *snd;
+	unsigned long flags;
+
+	if (!urb || !(snd = urb->context) || !(instance = snd->instance)) {
+		dbg ("udsl_complete_send: bad urb!");
+		return;
+	}
+
+	vdbg ("udsl_complete_send: urb 0x%p, status %d, snd 0x%p, buf 0x%p", urb, urb->status, snd, snd->buffer);
+
+	/* may not be in_interrupt() */
+	spin_lock_irqsave (&instance->send_lock, flags);
+	list_add (&snd->list, &instance->spare_senders);
+	list_add (&snd->buffer->list, &instance->spare_send_buffers);
+	tasklet_schedule (&instance->send_tasklet);
+	spin_unlock_irqrestore (&instance->send_lock, flags);
+}
+
+static void udsl_process_send (unsigned long data)
+{
+	struct udsl_send_buffer *buf;
+	struct udsl_instance_data *instance = (struct udsl_instance_data *) data;
+	struct sk_buff *skb;
+	struct udsl_sender *snd;
+	int err;
+	unsigned int num_written;
+
+made_progress:
+	spin_lock_irq (&instance->send_lock);
+	while (!list_empty (&instance->spare_senders)) {
+		if (!list_empty (&instance->filled_send_buffers)) {
+			buf = list_entry (instance->filled_send_buffers.next, struct udsl_send_buffer, list);
+			list_del (&buf->list);
+		} else if ((buf = instance->current_buffer)) {
+			instance->current_buffer = NULL;
+		} else /* all buffers empty */
+			break;
+
+		snd = list_entry (instance->spare_senders.next, struct udsl_sender, list);
+		list_del (&snd->list);
+		spin_unlock_irq (&instance->send_lock);
+
+		snd->buffer = buf;
+	        FILL_BULK_URB (snd->urb,
+			       instance->usb_dev,
+			       usb_sndbulkpipe (instance->usb_dev, UDSL_ENDPOINT_DATA_OUT),
+			       buf->base,
+			       (snd_buf_size - buf->free_cells) * ATM_CELL_SIZE,
+			       udsl_complete_send,
+			       snd);
+		snd->urb->transfer_flags |= USB_QUEUE_BULK;
+
+		vdbg ("udsl_process_send: submitting urb 0x%p (%d cells), snd 0x%p, buf 0x%p", snd->urb, snd_buf_size - buf->free_cells, snd, buf);
+
+		if ((err = usb_submit_urb(snd->urb)) < 0) {
+			dbg ("udsl_process_send: urb submission failed (%d)!", err);
+			spin_lock_irq (&instance->send_lock);
+			list_add (&snd->list, &instance->spare_senders);
+			spin_unlock_irq (&instance->send_lock);
+			list_add (&buf->list, &instance->filled_send_buffers);
+			return; /* bail out */
+		}
+
+		spin_lock_irq (&instance->send_lock);
+	} /* while */
+	spin_unlock_irq (&instance->send_lock);
+
+	if (!instance->current_skb && !(instance->current_skb = skb_dequeue (&instance->sndqueue)))
+		return; /* done - no more skbs */
+
+	skb = instance->current_skb;
+
+	if (!(buf = instance->current_buffer)) {
+		spin_lock_irq (&instance->send_lock);
+		if (list_empty (&instance->spare_send_buffers)) {
+			instance->current_buffer = NULL;
+			spin_unlock_irq (&instance->send_lock);
+			return; /* done - no more buffers */
+		}
+		buf = list_entry (instance->spare_send_buffers.next, struct udsl_send_buffer, list);
+		list_del (&buf->list);
+		spin_unlock_irq (&instance->send_lock);
+
+		buf->free_start = buf->base;
+		buf->free_cells = snd_buf_size;
+
+		instance->current_buffer = buf;
+	}
+
+	num_written = udsl_write_cells (buf->free_cells, skb, &buf->free_start);
+
+	vdbg ("udsl_process_send: wrote %u cells from skb 0x%p to buffer 0x%p", num_written, skb, buf);
+
+	if (!(buf->free_cells -= num_written)) {
+		list_add_tail (&buf->list, &instance->filled_send_buffers);
+		instance->current_buffer = NULL;
+	}
+
+	vdbg ("udsl_process_send: buffer contains %d cells, %d left", snd_buf_size - buf->free_cells, buf->free_cells);
+
+	if (!UDSL_SKB (skb)->num_cells) {
+		struct atm_vcc *vcc = UDSL_SKB (skb)->atm_data.vcc;
+
+		if (vcc->pop)
+			vcc->pop (vcc, skb);
+		else
+			dev_kfree_skb (skb);
+		instance->current_skb = NULL;
+
+		atomic_inc (&vcc->stats->tx);
+	}
+
+	goto made_progress;
+}
+
+static void udsl_cancel_send (struct udsl_instance_data *instance, struct atm_vcc *vcc)
+{
+	struct sk_buff *skb, *n;
+
+	dbg ("udsl_cancel_send entered");
+	spin_lock_irq (&instance->sndqueue.lock);
+	for (skb = instance->sndqueue.next, n = skb->next; skb != (struct sk_buff *)&instance->sndqueue; skb = n, n = skb->next)
+		if (UDSL_SKB (skb)->atm_data.vcc == vcc) {
+			dbg ("udsl_cancel_send: popping skb 0x%p", skb);
+			__skb_unlink (skb, &instance->sndqueue);
+			if (vcc->pop)
+				vcc->pop (vcc, skb);
+			else
+				dev_kfree_skb (skb);
+		}
+	spin_unlock_irq (&instance->sndqueue.lock);
+
+	tasklet_disable (&instance->send_tasklet);
+	if ((skb = instance->current_skb) && (UDSL_SKB (skb)->atm_data.vcc == vcc)) {
+		dbg ("udsl_cancel_send: popping current skb (0x%p)", skb);
+		instance->current_skb = NULL;
+		if (vcc->pop)
+			vcc->pop (vcc, skb);
+		else
+			dev_kfree_skb (skb);
+	}
+	tasklet_enable (&instance->send_tasklet);
+	dbg ("udsl_cancel_send done");
+}
+
+static int udsl_atm_send (struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	struct udsl_instance_data *instance = vcc->dev->dev_data;
+
+	vdbg ("udsl_atm_send called (skb 0x%p, len %u)", skb, skb->len);
+
+	if (!instance || !instance->usb_dev) {
+		dbg ("udsl_atm_send: NULL data!");
+		return -ENODEV;
+	}
+
+	if (vcc->qos.aal != ATM_AAL5) {
+		dbg ("udsl_atm_send: unsupported ATM type %d!", vcc->qos.aal);
+		return -EINVAL;
+	}
+
+	if (skb->len > ATM_MAX_AAL5_PDU) {
+		dbg ("udsl_atm_send: packet too long (%d vs %d)!", skb->len, ATM_MAX_AAL5_PDU);
+		return -EINVAL;
+	}
+
+	PACKETDEBUG (skb->data, skb->len);
+
+	udsl_groom_skb (vcc, skb);
+	skb_queue_tail (&instance->sndqueue, skb);
+	tasklet_schedule (&instance->send_tasklet);
+
+	return 0;
+}
+
+
+/**********
+**  ATM  **
+**********/
+
+static void udsl_atm_dev_close (struct atm_dev *dev)
+{
+	struct udsl_instance_data *instance = dev->dev_data;
+
+	if (!instance) {
+		dbg ("udsl_atm_dev_close: NULL instance!");
+		return;
+	}
+
+	dbg ("udsl_atm_dev_close: queue has %u elements", instance->sndqueue.qlen);
+
+	tasklet_kill (&instance->receive_tasklet);
+	tasklet_kill (&instance->send_tasklet);
+	kfree (instance);
+	dev->dev_data = NULL;
+}
+
+static int udsl_atm_proc_read (struct atm_dev *atm_dev, loff_t *pos, char *page)
+{
+	struct udsl_instance_data *instance = atm_dev->dev_data;
+	int left = *pos;
+
+	if (!instance) {
+		dbg ("udsl_atm_proc_read: NULL instance!");
+		return -ENODEV;
+	}
+
+	if (!left--)
+		return sprintf (page, "%s\n", instance->description);
+
+	if (!left--)
+		return sprintf (page, "MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
+				atm_dev->esi [0], atm_dev->esi [1], atm_dev->esi [2],
+				atm_dev->esi [3], atm_dev->esi [4], atm_dev->esi [5]);
+
+	if (!left--)
+		return sprintf (page, "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
+				atomic_read (&atm_dev->stats.aal5.tx),
+				atomic_read (&atm_dev->stats.aal5.tx_err),
+				atomic_read (&atm_dev->stats.aal5.rx),
+				atomic_read (&atm_dev->stats.aal5.rx_err),
+				atomic_read (&atm_dev->stats.aal5.rx_drop));
+
+	if (!left--) {
+		switch (atm_dev->signal) {
+		case ATM_PHY_SIG_FOUND:
+			sprintf (page, "Line up");
+			break;
+		case ATM_PHY_SIG_LOST:
+			sprintf (page, "Line down");
+			break;
+		default:
+			sprintf (page, "Line state unknown");
+			break;
+		}
+
+		if (instance->usb_dev) {
+			if (!instance->firmware_loaded)
+				strcat (page, ", no firmware\n");
+			else
+				strcat (page, ", firmware loaded\n");
+		} else
+			strcat (page, ", disconnected\n");
+
+		return strlen (page);
+	}
+
+	return 0;
+}
+
+static int udsl_atm_open (struct atm_vcc *vcc, short vpi, int vci)
+{
+	struct udsl_instance_data *instance = vcc->dev->dev_data;
+	struct udsl_vcc_data *new;
+
+	dbg ("udsl_atm_open: vpi %hd, vci %d", vpi, vci);
+
+	if (!instance || !instance->usb_dev) {
+		dbg ("udsl_atm_open: NULL data!");
+		return -ENODEV;
+	}
+
+	if ((vpi == ATM_VPI_ANY) || (vci == ATM_VCI_ANY))
+		return -EINVAL;
+
+	/* only support AAL5 */
+	if ((vcc->qos.aal != ATM_AAL5) || (vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU))
+		return -EINVAL;
+
+	if (!instance->firmware_loaded) {
+		dbg ("udsl_atm_open: firmware not loaded!");
+		return -EAGAIN;
+	}
+
+	down (&instance->serialize); /* vs self, udsl_atm_close */
+
+	if (udsl_find_vcc (instance, vpi, vci)) {
+		up (&instance->serialize);
+		return -EADDRINUSE;
+	}
+
+	if (!(new = kmalloc (sizeof (struct udsl_vcc_data), GFP_KERNEL))) {
+		up (&instance->serialize);
+		return -ENOMEM;
+	}
+
+	memset (new, 0, sizeof (struct udsl_vcc_data));
+	new->vcc = vcc;
+	new->vpi = vpi;
+	new->vci = vci;
+	new->max_pdu = max (1, UDSL_NUM_CELLS (vcc->qos.rxtp.max_sdu)) * ATM_CELL_PAYLOAD;
+
+	vcc->dev_data = new;
+	vcc->vpi = vpi;
+	vcc->vci = vci;
+
+	tasklet_disable (&instance->receive_tasklet);
+	list_add (&new->list, &instance->vcc_list);
+	tasklet_enable (&instance->receive_tasklet);
+
+	set_bit (ATM_VF_ADDR, &vcc->flags);
+	set_bit (ATM_VF_PARTIAL, &vcc->flags);
+	set_bit (ATM_VF_READY, &vcc->flags);
+
+	up (&instance->serialize);
+
+	tasklet_schedule (&instance->receive_tasklet);
+
+	dbg ("udsl_atm_open: allocated vcc data 0x%p (max_pdu: %u)", new, new->max_pdu);
+
+	return 0;
+}
+
+static void udsl_atm_close (struct atm_vcc *vcc)
+{
+	struct udsl_instance_data *instance = vcc->dev->dev_data;
+	struct udsl_vcc_data *vcc_data = vcc->dev_data;
+
+	dbg ("udsl_atm_close called");
+
+	if (!instance || !vcc_data) {
+		dbg ("udsl_atm_close: NULL data!");
+		return;
+	}
+
+	dbg ("udsl_atm_close: deallocating vcc 0x%p with vpi %d vci %d", vcc_data, vcc_data->vpi, vcc_data->vci);
+
+	udsl_cancel_send (instance, vcc);
+
+	down (&instance->serialize); /* vs self, udsl_atm_open */
+
+	tasklet_disable (&instance->receive_tasklet);
+	list_del (&vcc_data->list);
+	tasklet_enable (&instance->receive_tasklet);
+
+	if (vcc_data->skb)
+		dev_kfree_skb (vcc_data->skb);
+	vcc_data->skb = NULL;
+
+	kfree (vcc_data);
+	vcc->dev_data = NULL;
+
+	vcc->vpi = ATM_VPI_UNSPEC;
+	vcc->vci = ATM_VCI_UNSPEC;
+	clear_bit (ATM_VF_READY, &vcc->flags);
+	clear_bit (ATM_VF_PARTIAL, &vcc->flags);
+	clear_bit (ATM_VF_ADDR, &vcc->flags);
+
+	up (&instance->serialize);
+
+	dbg ("udsl_atm_close successful");
+}
+
+static int udsl_atm_ioctl (struct atm_dev *dev, unsigned int cmd, void *arg)
+{
+	switch (cmd) {
+	case ATM_QUERYLOOP:
+		return put_user (ATM_LM_NONE, (int *) arg) ? -EFAULT : 0;
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+
+/**********
+**  USB  **
+**********/
+
+static int udsl_set_alternate (struct udsl_instance_data *instance)
+{
+	down (&instance->serialize); /* vs self */
+	if (!instance->firmware_loaded) {
+		int ret;
+
+		if ((ret = usb_set_interface (instance->usb_dev, 1, 1)) < 0) {
+			dbg ("udsl_set_alternate: usb_set_interface returned %d!", ret);
+			up (&instance->serialize);
+			return ret;
+		}
+		instance->firmware_loaded = 1;
+	}
+	up (&instance->serialize);
+
+	tasklet_schedule (&instance->receive_tasklet);
+
+	return 0;
+}
+
+static int udsl_usb_ioctl (struct usb_device *dev, unsigned int code, void *user_data)
+{
+	struct usb_interface *intf = usb_ifnum_to_if (dev, 1);
+	struct udsl_instance_data *instance = intf->private_data;
+
+	dbg ("udsl_usb_ioctl entered");
+
+	if (!instance) {
+		dbg ("udsl_usb_ioctl: NULL instance!");
+		return -ENODEV;
+	}
+
+	switch (code) {
+	case UDSL_IOCTL_LINE_UP:
+		instance->atm_dev->signal = ATM_PHY_SIG_FOUND;
+		return udsl_set_alternate (instance);
+	case UDSL_IOCTL_LINE_DOWN:
+		instance->atm_dev->signal = ATM_PHY_SIG_LOST;
+		return 0;
+	default:
+		return -ENOTTY;
+	}
+}
+
+static void *udsl_usb_probe (struct usb_device *dev, unsigned int ifnum, const struct usb_device_id *id)
+{
+	struct udsl_instance_data *instance;
+	unsigned char mac_str [13];
+	int i, length;
+	char *buf;
+
+	dbg ("udsl_usb_probe: trying device with vendor=0x%x, product=0x%x, ifnum %d",
+	     dev->descriptor.idVendor, dev->descriptor.idProduct, ifnum);
+
+	if ((dev->descriptor.bDeviceClass != USB_CLASS_VENDOR_SPEC) ||
+	    (dev->descriptor.idVendor != SPEEDTOUCH_VENDORID) ||
+	    (dev->descriptor.idProduct != SPEEDTOUCH_PRODUCTID) || (ifnum != 1))
+		return NULL;
+
+	dbg ("udsl_usb_probe: device accepted");
+
+	/* instance init */
+	if (!(instance = kmalloc (sizeof (struct udsl_instance_data), GFP_KERNEL))) {
+		dbg ("udsl_usb_probe: no memory for instance data!");
+		return NULL;
+	}
+
+	memset (instance, 0, sizeof (struct udsl_instance_data));
+
+	init_MUTEX (&instance->serialize);
+
+	instance->usb_dev = dev;
+
+	INIT_LIST_HEAD (&instance->vcc_list);
+
+	spin_lock_init (&instance->receive_lock);
+	INIT_LIST_HEAD (&instance->spare_receivers);
+	INIT_LIST_HEAD (&instance->filled_receive_buffers);
+
+	tasklet_init (&instance->receive_tasklet, udsl_process_receive, (unsigned long) instance);
+	INIT_LIST_HEAD (&instance->spare_receive_buffers);
+
+	skb_queue_head_init (&instance->sndqueue);
+
+	spin_lock_init (&instance->send_lock);
+	INIT_LIST_HEAD (&instance->spare_senders);
+	INIT_LIST_HEAD (&instance->spare_send_buffers);
+
+	tasklet_init (&instance->send_tasklet, udsl_process_send, (unsigned long) instance);
+	INIT_LIST_HEAD (&instance->filled_send_buffers);
+
+	/* receive init */
+	for (i = 0; i < num_rcv_urbs; i++) {
+		struct udsl_receiver *rcv = &(instance->receivers [i]);
+
+		if (!(rcv->urb = usb_alloc_urb (0))) {
+			dbg ("udsl_usb_probe: no memory for receive urb %d!", i);
+			goto fail;
+		}
+
+		rcv->instance = instance;
+
+		list_add (&rcv->list, &instance->spare_receivers);
+	}
+
+	for (i = 0; i < num_rcv_bufs; i++) {
+		struct udsl_receive_buffer *buf = &(instance->receive_buffers [i]);
+
+		if (!(buf->base = kmalloc (rcv_buf_size * ATM_CELL_SIZE, GFP_KERNEL))) {
+			dbg ("udsl_usb_probe: no memory for receive buffer %d!", i);
+			goto fail;
+		}
+
+		list_add (&buf->list, &instance->spare_receive_buffers);
+	}
+
+	/* send init */
+	for (i = 0; i < num_snd_urbs; i++) {
+		struct udsl_sender *snd = &(instance->senders [i]);
+
+		if (!(snd->urb = usb_alloc_urb (0))) {
+			dbg ("udsl_usb_probe: no memory for send urb %d!", i);
+			goto fail;
+		}
+
+		snd->instance = instance;
+
+		list_add (&snd->list, &instance->spare_senders);
+	}
+
+	for (i = 0; i < num_snd_bufs; i++) {
+		struct udsl_send_buffer *buf = &(instance->send_buffers [i]);
+
+		if (!(buf->base = kmalloc (snd_buf_size * ATM_CELL_SIZE, GFP_KERNEL))) {
+			dbg ("udsl_usb_probe: no memory for send buffer %d!", i);
+			goto fail;
+		}
+
+		list_add (&buf->list, &instance->spare_send_buffers);
+	}
+
+	/* ATM init */
+	if (!(instance->atm_dev = atm_dev_register (udsl_driver_name, &udsl_atm_devops, -1, 0))) {
+		dbg ("udsl_usb_probe: failed to register ATM device!");
+		goto fail;
+	}
+
+	instance->atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
+	instance->atm_dev->ci_range.vci_bits = ATM_CI_MAX;
+	instance->atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
+
+	/* temp init ATM device, set to 128kbit */
+	instance->atm_dev->link_rate = 128 * 1000 / 424;
+
+	/* set MAC address, it is stored in the serial number */
+	memset (instance->atm_dev->esi, 0, sizeof (instance->atm_dev->esi));
+	if (usb_string (dev, dev->descriptor.iSerialNumber, mac_str, sizeof (mac_str)) == 12)
+		for (i = 0; i < 6; i++)
+			instance->atm_dev->esi [i] = (hex2int (mac_str [i * 2]) * 16) + (hex2int (mac_str [i * 2 + 1]));
+
+	/* device description */
+	buf = instance->description;
+	length = sizeof (instance->description);
+
+	if ((i = usb_string (dev, dev->descriptor.iProduct, buf, length)) < 0)
+		goto finish;
+
+	buf += i;
+	length -= i;
+
+	i = snprintf (buf, length, " (");
+	buf += i;
+	length -= i;
+
+	if (length <= 0 || (i = usb_make_path (dev, buf, length)) < 0)
+		goto finish;
+
+	buf += i;
+	length -= i;
+
+	snprintf (buf, length, ")");
+
+finish:
+	/* ready for ATM callbacks */
+	wmb ();
+	instance->atm_dev->dev_data = instance;
+
+	return instance;
+
+fail:
+	for (i = 0; i < num_snd_bufs; i++)
+		kfree (instance->send_buffers [i].base);
+
+	for (i = 0; i < num_snd_urbs; i++)
+		usb_free_urb (instance->senders [i].urb);
+
+	for (i = 0; i < num_rcv_bufs; i++)
+		kfree (instance->receive_buffers [i].base);
+
+	for (i = 0; i < num_rcv_urbs; i++)
+		usb_free_urb (instance->receivers [i].urb);
+
+	kfree (instance);
+
+	return NULL;
+}
+
+static void udsl_usb_disconnect (struct usb_device *dev, void *ptr)
+{
+	struct udsl_instance_data *instance = ptr;
+	struct list_head *pos;
+	unsigned int count;
+	int result, i;
+
+	dbg ("udsl_usb_disconnect entered");
+
+	if (!instance) {
+		dbg ("udsl_usb_disconnect: NULL instance!");
+		return;
+	}
+
+	/* receive finalize */
+	tasklet_disable (&instance->receive_tasklet);
+
+	for (i = 0; i < num_rcv_urbs; i++)
+		if ((result = usb_unlink_urb (instance->receivers [i].urb)) < 0)
+			dbg ("udsl_usb_disconnect: usb_unlink_urb on receive urb %d returned %d", i, result);
+
+	/* wait for completion handlers to finish */
+	do {
+		count = 0;
+		spin_lock_irq (&instance->receive_lock);
+		list_for_each (pos, &instance->spare_receivers)
+			if (++count > num_rcv_urbs)
+				panic (__FILE__ ": memory corruption detected at line %d!\n", __LINE__);
+		spin_unlock_irq (&instance->receive_lock);
+
+		dbg ("udsl_usb_disconnect: found %u spare receivers", count);
+
+		if (count == num_rcv_urbs)
+			break;
+
+		set_current_state (TASK_RUNNING);
+		schedule ();
+	} while (1);
+
+	/* no need to take the spinlock */
+	INIT_LIST_HEAD (&instance->filled_receive_buffers);
+	INIT_LIST_HEAD (&instance->spare_receive_buffers);
+
+	tasklet_enable (&instance->receive_tasklet);
+
+	for (i = 0; i < num_rcv_urbs; i++)
+		usb_free_urb (instance->receivers [i].urb);
+
+	for (i = 0; i < num_rcv_bufs; i++)
+		kfree (instance->receive_buffers [i].base);
+
+	/* send finalize */
+	tasklet_disable (&instance->send_tasklet);
+
+	for (i = 0; i < num_snd_urbs; i++)
+		if ((result = usb_unlink_urb (instance->senders [i].urb)) < 0)
+			dbg ("udsl_usb_disconnect: usb_unlink_urb on send urb %d returned %d", i, result);
+
+	/* wait for completion handlers to finish */
+	do {
+		count = 0;
+		spin_lock_irq (&instance->send_lock);
+		list_for_each (pos, &instance->spare_senders)
+			if (++count > num_snd_urbs)
+				panic (__FILE__ ": memory corruption detected at line %d!\n", __LINE__);
+		spin_unlock_irq (&instance->send_lock);
+
+		dbg ("udsl_usb_disconnect: found %u spare senders", count);
+
+		if (count == num_snd_urbs)
+			break;
+
+		set_current_state (TASK_RUNNING);
+		schedule ();
+	} while (1);
+
+	/* no need to take the spinlock */
+	INIT_LIST_HEAD (&instance->spare_senders);
+	INIT_LIST_HEAD (&instance->spare_send_buffers);
+	instance->current_buffer = NULL;
+
+	tasklet_enable (&instance->send_tasklet);
+
+	for (i = 0; i < num_snd_urbs; i++)
+		usb_free_urb (instance->senders [i].urb);
+
+	for (i = 0; i < num_snd_bufs; i++)
+		kfree (instance->send_buffers [i].base);
+
+	wmb ();
+	instance->usb_dev = NULL;
+
+	/* ATM finalize */
+	shutdown_atm_dev (instance->atm_dev); /* frees instance, kills tasklets */
+}
+
+
+/***********
+**  init  **
+***********/
+
+static int __init udsl_usb_init (void)
+{
+	struct sk_buff *skb; /* dummy for sizeof */
+
+	dbg ("udsl_usb_init: driver version " DRIVER_VERSION);
+
+	if (sizeof (struct udsl_control) > sizeof (skb->cb)) {
+		printk (KERN_ERR __FILE__ ": unusable with this kernel!\n");
+		return -EIO;
+	}
+
+	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS) || (num_snd_urbs > UDSL_MAX_SND_URBS) ||
+	    (num_rcv_bufs > UDSL_MAX_RCV_BUFS) || (num_snd_bufs > UDSL_MAX_SND_BUFS) ||
+	    (rcv_buf_size > UDSL_MAX_RCV_BUF_SIZE) || (snd_buf_size > UDSL_MAX_SND_BUF_SIZE))
+		return -EINVAL;
+
+	return usb_register (&udsl_usb_driver);
+}
+
+static void __exit udsl_usb_cleanup (void)
+{
+	dbg ("udsl_usb_cleanup entered");
+
+	usb_deregister (&udsl_usb_driver);
+}
+
+module_init (udsl_usb_init);
+module_exit (udsl_usb_cleanup);
+
+MODULE_AUTHOR (DRIVER_AUTHOR);
+MODULE_DESCRIPTION (DRIVER_DESC);
+MODULE_LICENSE ("GPL");
+
+
+/************
+**  debug  **
+************/
+
+#ifdef VERBOSE_DEBUG
+static int udsl_print_packet (const unsigned char *data, int len)
+{
+	unsigned char buffer [256];
+	int i = 0, j = 0;
+
+	for (i = 0; i < len;) {
+		buffer [0] = '\0';
+		sprintf (buffer, "%.3d :", i);
+		for (j = 0; (j < 16) && (i < len); j++, i++) {
+			sprintf (buffer, "%s %2.2x", buffer, data [i]);
+		}
+		dbg ("%s", buffer);
+	}
+	return i;
+}
+#endif
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TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)