xref: /openbmc/linux/drivers/usb/atm/usbatm.c (revision 6dfcd296)
1 /******************************************************************************
2  *  usbatm.c - Generic USB xDSL driver core
3  *
4  *  Copyright (C) 2001, Alcatel
5  *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
6  *  Copyright (C) 2004, David Woodhouse, Roman Kagan
7  *
8  *  This program is free software; you can redistribute it and/or modify it
9  *  under the terms of the GNU General Public License as published by the Free
10  *  Software Foundation; either version 2 of the License, or (at your option)
11  *  any later version.
12  *
13  *  This program is distributed in the hope that it will be useful, but WITHOUT
14  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  *  more details.
17  *
18  *  You should have received a copy of the GNU General Public License along with
19  *  this program; if not, write to the Free Software Foundation, Inc., 59
20  *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
21  *
22  ******************************************************************************/
23 
24 /*
25  *  Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
26  *
27  *  1.7+:	- See the check-in logs
28  *
29  *  1.6:	- No longer opens a connection if the firmware is not loaded
30  *  		- Added support for the speedtouch 330
31  *  		- Removed the limit on the number of devices
32  *  		- Module now autoloads on device plugin
33  *  		- Merged relevant parts of sarlib
34  *  		- Replaced the kernel thread with a tasklet
35  *  		- New packet transmission code
36  *  		- Changed proc file contents
37  *  		- Fixed all known SMP races
38  *  		- Many fixes and cleanups
39  *  		- Various fixes by Oliver Neukum (oliver@neukum.name)
40  *
41  *  1.5A:	- Version for inclusion in 2.5 series kernel
42  *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
43  *		- made compatible with kernel 2.5.6 onwards by changing
44  *		usbatm_usb_send_data_context->urb to a pointer and adding code
45  *		to alloc and free it
46  *		- remove_wait_queue() added to usbatm_atm_processqueue_thread()
47  *
48  *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
49  *		(reported by stephen.robinson@zen.co.uk)
50  *
51  *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
52  *		- unlink all active send urbs of a vcc that is being closed.
53  *
54  *  1.3.1:	- added the version number
55  *
56  *  1.3:	- Added multiple send urb support
57  *		- fixed memory leak and vcc->tx_inuse starvation bug
58  *		  when not enough memory left in vcc.
59  *
60  *  1.2:	- Fixed race condition in usbatm_usb_send_data()
61  *  1.1:	- Turned off packet debugging
62  *
63  */
64 
65 #include "usbatm.h"
66 
67 #include <asm/uaccess.h>
68 #include <linux/crc32.h>
69 #include <linux/errno.h>
70 #include <linux/init.h>
71 #include <linux/interrupt.h>
72 #include <linux/kernel.h>
73 #include <linux/module.h>
74 #include <linux/moduleparam.h>
75 #include <linux/netdevice.h>
76 #include <linux/proc_fs.h>
77 #include <linux/sched.h>
78 #include <linux/signal.h>
79 #include <linux/slab.h>
80 #include <linux/stat.h>
81 #include <linux/timer.h>
82 #include <linux/wait.h>
83 #include <linux/kthread.h>
84 #include <linux/ratelimit.h>
85 
86 #ifdef VERBOSE_DEBUG
87 static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
88 #define PACKETDEBUG(arg...)	usbatm_print_packet(arg)
89 #define vdbg(arg...)		dev_dbg(arg)
90 #else
91 #define PACKETDEBUG(arg...)
92 #define vdbg(arg...)
93 #endif
94 
95 #define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
96 #define DRIVER_VERSION	"1.10"
97 #define DRIVER_DESC	"Generic USB ATM/DSL I/O, version " DRIVER_VERSION
98 
99 static const char usbatm_driver_name[] = "usbatm";
100 
101 #define UDSL_MAX_RCV_URBS		16
102 #define UDSL_MAX_SND_URBS		16
103 #define UDSL_MAX_BUF_SIZE		65536
104 #define UDSL_DEFAULT_RCV_URBS		4
105 #define UDSL_DEFAULT_SND_URBS		4
106 #define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
107 #define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
108 
109 #define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
110 
111 #define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */
112 
113 static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
114 static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
115 static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
116 static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
117 
118 module_param(num_rcv_urbs, uint, S_IRUGO);
119 MODULE_PARM_DESC(num_rcv_urbs,
120 		 "Number of urbs used for reception (range: 0-"
121 		 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
122 		 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
123 
124 module_param(num_snd_urbs, uint, S_IRUGO);
125 MODULE_PARM_DESC(num_snd_urbs,
126 		 "Number of urbs used for transmission (range: 0-"
127 		 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
128 		 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
129 
130 module_param(rcv_buf_bytes, uint, S_IRUGO);
131 MODULE_PARM_DESC(rcv_buf_bytes,
132 		 "Size of the buffers used for reception, in bytes (range: 1-"
133 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
134 		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
135 
136 module_param(snd_buf_bytes, uint, S_IRUGO);
137 MODULE_PARM_DESC(snd_buf_bytes,
138 		 "Size of the buffers used for transmission, in bytes (range: 1-"
139 		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
140 		 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
141 
142 
143 /* receive */
144 
145 struct usbatm_vcc_data {
146 	/* vpi/vci lookup */
147 	struct list_head list;
148 	short vpi;
149 	int vci;
150 	struct atm_vcc *vcc;
151 
152 	/* raw cell reassembly */
153 	struct sk_buff *sarb;
154 };
155 
156 
157 /* send */
158 
159 struct usbatm_control {
160 	struct atm_skb_data atm;
161 	u32 len;
162 	u32 crc;
163 };
164 
165 #define UDSL_SKB(x)		((struct usbatm_control *)(x)->cb)
166 
167 
168 /* ATM */
169 
170 static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
171 static int usbatm_atm_open(struct atm_vcc *vcc);
172 static void usbatm_atm_close(struct atm_vcc *vcc);
173 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
174 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
175 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
176 
177 static struct atmdev_ops usbatm_atm_devops = {
178 	.dev_close	= usbatm_atm_dev_close,
179 	.open		= usbatm_atm_open,
180 	.close		= usbatm_atm_close,
181 	.ioctl		= usbatm_atm_ioctl,
182 	.send		= usbatm_atm_send,
183 	.proc_read	= usbatm_atm_proc_read,
184 	.owner		= THIS_MODULE,
185 };
186 
187 
188 /***********
189 **  misc  **
190 ***********/
191 
192 static inline unsigned int usbatm_pdu_length(unsigned int length)
193 {
194 	length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
195 	return length - length % ATM_CELL_PAYLOAD;
196 }
197 
198 static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
199 {
200 	if (vcc->pop)
201 		vcc->pop(vcc, skb);
202 	else
203 		dev_kfree_skb_any(skb);
204 }
205 
206 
207 /***********
208 **  urbs  **
209 ************/
210 
211 static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
212 {
213 	struct urb *urb;
214 
215 	spin_lock_irq(&channel->lock);
216 	if (list_empty(&channel->list)) {
217 		spin_unlock_irq(&channel->lock);
218 		return NULL;
219 	}
220 
221 	urb = list_entry(channel->list.next, struct urb, urb_list);
222 	list_del(&urb->urb_list);
223 	spin_unlock_irq(&channel->lock);
224 
225 	return urb;
226 }
227 
228 static int usbatm_submit_urb(struct urb *urb)
229 {
230 	struct usbatm_channel *channel = urb->context;
231 	int ret;
232 
233 	/* vdbg("%s: submitting urb 0x%p, size %u",
234 	     __func__, urb, urb->transfer_buffer_length); */
235 
236 	ret = usb_submit_urb(urb, GFP_ATOMIC);
237 	if (ret) {
238 		if (printk_ratelimit())
239 			atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
240 				__func__, urb, ret);
241 
242 		/* consider all errors transient and return the buffer back to the queue */
243 		urb->status = -EAGAIN;
244 		spin_lock_irq(&channel->lock);
245 
246 		/* must add to the front when sending; doesn't matter when receiving */
247 		list_add(&urb->urb_list, &channel->list);
248 
249 		spin_unlock_irq(&channel->lock);
250 
251 		/* make sure the channel doesn't stall */
252 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
253 	}
254 
255 	return ret;
256 }
257 
258 static void usbatm_complete(struct urb *urb)
259 {
260 	struct usbatm_channel *channel = urb->context;
261 	unsigned long flags;
262 	int status = urb->status;
263 
264 	/* vdbg("%s: urb 0x%p, status %d, actual_length %d",
265 	     __func__, urb, status, urb->actual_length); */
266 
267 	/* usually in_interrupt(), but not always */
268 	spin_lock_irqsave(&channel->lock, flags);
269 
270 	/* must add to the back when receiving; doesn't matter when sending */
271 	list_add_tail(&urb->urb_list, &channel->list);
272 
273 	spin_unlock_irqrestore(&channel->lock, flags);
274 
275 	if (unlikely(status) &&
276 			(!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
277 			 status != -EILSEQ)) {
278 		if (status == -ESHUTDOWN)
279 			return;
280 
281 		if (printk_ratelimit())
282 			atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
283 				__func__, urb, status);
284 		/* throttle processing in case of an error */
285 		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
286 	} else
287 		tasklet_schedule(&channel->tasklet);
288 }
289 
290 
291 /*************
292 **  decode  **
293 *************/
294 
295 static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
296 						  short vpi, int vci)
297 {
298 	struct usbatm_vcc_data *vcc_data;
299 
300 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
301 		if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
302 			return vcc_data;
303 	return NULL;
304 }
305 
306 static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
307 {
308 	struct atm_vcc *vcc;
309 	struct sk_buff *sarb;
310 	short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
311 	int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
312 	u8 pti = ((source[3] & 0xe) >> 1);
313 
314 	if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
315 		instance->cached_vpi = vpi;
316 		instance->cached_vci = vci;
317 
318 		instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
319 
320 		if (!instance->cached_vcc)
321 			atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
322 	}
323 
324 	if (!instance->cached_vcc)
325 		return;
326 
327 	vcc = instance->cached_vcc->vcc;
328 
329 	/* OAM F5 end-to-end */
330 	if (pti == ATM_PTI_E2EF5) {
331 		if (printk_ratelimit())
332 			atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
333 				__func__, vpi, vci);
334 		atomic_inc(&vcc->stats->rx_err);
335 		return;
336 	}
337 
338 	sarb = instance->cached_vcc->sarb;
339 
340 	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
341 		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
342 				__func__, sarb->len, vcc);
343 		/* discard cells already received */
344 		skb_trim(sarb, 0);
345 	}
346 
347 	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
348 	__skb_put(sarb, ATM_CELL_PAYLOAD);
349 
350 	if (pti & 1) {
351 		struct sk_buff *skb;
352 		unsigned int length;
353 		unsigned int pdu_length;
354 
355 		length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
356 
357 		/* guard against overflow */
358 		if (length > ATM_MAX_AAL5_PDU) {
359 			atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
360 				  __func__, length, vcc);
361 			atomic_inc(&vcc->stats->rx_err);
362 			goto out;
363 		}
364 
365 		pdu_length = usbatm_pdu_length(length);
366 
367 		if (sarb->len < pdu_length) {
368 			atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
369 				  __func__, pdu_length, sarb->len, vcc);
370 			atomic_inc(&vcc->stats->rx_err);
371 			goto out;
372 		}
373 
374 		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
375 			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
376 				  __func__, vcc);
377 			atomic_inc(&vcc->stats->rx_err);
378 			goto out;
379 		}
380 
381 		vdbg(&instance->usb_intf->dev,
382 		     "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
383 		     __func__, length, pdu_length, vcc);
384 
385 		skb = dev_alloc_skb(length);
386 		if (!skb) {
387 			if (printk_ratelimit())
388 				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
389 					__func__, length);
390 			atomic_inc(&vcc->stats->rx_drop);
391 			goto out;
392 		}
393 
394 		vdbg(&instance->usb_intf->dev,
395 		     "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
396 		     __func__, skb, skb->truesize);
397 
398 		if (!atm_charge(vcc, skb->truesize)) {
399 			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
400 				  __func__, skb->truesize);
401 			dev_kfree_skb_any(skb);
402 			goto out;	/* atm_charge increments rx_drop */
403 		}
404 
405 		skb_copy_to_linear_data(skb,
406 					skb_tail_pointer(sarb) - pdu_length,
407 					length);
408 		__skb_put(skb, length);
409 
410 		vdbg(&instance->usb_intf->dev,
411 		     "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
412 		     __func__, skb, skb->len, skb->truesize);
413 
414 		PACKETDEBUG(instance, skb->data, skb->len);
415 
416 		vcc->push(vcc, skb);
417 
418 		atomic_inc(&vcc->stats->rx);
419 	out:
420 		skb_trim(sarb, 0);
421 	}
422 }
423 
424 static void usbatm_extract_cells(struct usbatm_data *instance,
425 		unsigned char *source, unsigned int avail_data)
426 {
427 	unsigned int stride = instance->rx_channel.stride;
428 	unsigned int buf_usage = instance->buf_usage;
429 
430 	/* extract cells from incoming data, taking into account that
431 	 * the length of avail data may not be a multiple of stride */
432 
433 	if (buf_usage > 0) {
434 		/* we have a partially received atm cell */
435 		unsigned char *cell_buf = instance->cell_buf;
436 		unsigned int space_left = stride - buf_usage;
437 
438 		if (avail_data >= space_left) {
439 			/* add new data and process cell */
440 			memcpy(cell_buf + buf_usage, source, space_left);
441 			source += space_left;
442 			avail_data -= space_left;
443 			usbatm_extract_one_cell(instance, cell_buf);
444 			instance->buf_usage = 0;
445 		} else {
446 			/* not enough data to fill the cell */
447 			memcpy(cell_buf + buf_usage, source, avail_data);
448 			instance->buf_usage = buf_usage + avail_data;
449 			return;
450 		}
451 	}
452 
453 	for (; avail_data >= stride; avail_data -= stride, source += stride)
454 		usbatm_extract_one_cell(instance, source);
455 
456 	if (avail_data > 0) {
457 		/* length was not a multiple of stride -
458 		 * save remaining data for next call */
459 		memcpy(instance->cell_buf, source, avail_data);
460 		instance->buf_usage = avail_data;
461 	}
462 }
463 
464 
465 /*************
466 **  encode  **
467 *************/
468 
469 static unsigned int usbatm_write_cells(struct usbatm_data *instance,
470 				       struct sk_buff *skb,
471 				       u8 *target, unsigned int avail_space)
472 {
473 	struct usbatm_control *ctrl = UDSL_SKB(skb);
474 	struct atm_vcc *vcc = ctrl->atm.vcc;
475 	unsigned int bytes_written;
476 	unsigned int stride = instance->tx_channel.stride;
477 
478 	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
479 	     bytes_written += stride, target += stride) {
480 		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
481 		unsigned int left = ATM_CELL_PAYLOAD - data_len;
482 		u8 *ptr = target;
483 
484 		ptr[0] = vcc->vpi >> 4;
485 		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
486 		ptr[2] = vcc->vci >> 4;
487 		ptr[3] = vcc->vci << 4;
488 		ptr[4] = 0xec;
489 		ptr += ATM_CELL_HEADER;
490 
491 		skb_copy_from_linear_data(skb, ptr, data_len);
492 		ptr += data_len;
493 		__skb_pull(skb, data_len);
494 
495 		if (!left)
496 			continue;
497 
498 		memset(ptr, 0, left);
499 
500 		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
501 			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
502 			/* trailer[0] = 0;		UU = 0 */
503 			/* trailer[1] = 0;		CPI = 0 */
504 			trailer[2] = ctrl->len >> 8;
505 			trailer[3] = ctrl->len;
506 
507 			ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
508 
509 			trailer[4] = ctrl->crc >> 24;
510 			trailer[5] = ctrl->crc >> 16;
511 			trailer[6] = ctrl->crc >> 8;
512 			trailer[7] = ctrl->crc;
513 
514 			target[3] |= 0x2;	/* adjust PTI */
515 
516 			ctrl->len = 0;		/* tag this skb finished */
517 		} else
518 			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
519 	}
520 
521 	return bytes_written;
522 }
523 
524 
525 /**************
526 **  receive  **
527 **************/
528 
529 static void usbatm_rx_process(unsigned long data)
530 {
531 	struct usbatm_data *instance = (struct usbatm_data *)data;
532 	struct urb *urb;
533 
534 	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
535 		vdbg(&instance->usb_intf->dev,
536 		     "%s: processing urb 0x%p", __func__, urb);
537 
538 		if (usb_pipeisoc(urb->pipe)) {
539 			unsigned char *merge_start = NULL;
540 			unsigned int merge_length = 0;
541 			const unsigned int packet_size = instance->rx_channel.packet_size;
542 			int i;
543 
544 			for (i = 0; i < urb->number_of_packets; i++) {
545 				if (!urb->iso_frame_desc[i].status) {
546 					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
547 
548 					if (!merge_length)
549 						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
550 					merge_length += actual_length;
551 					if (merge_length && (actual_length < packet_size)) {
552 						usbatm_extract_cells(instance, merge_start, merge_length);
553 						merge_length = 0;
554 					}
555 				} else {
556 					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
557 					if (merge_length)
558 						usbatm_extract_cells(instance, merge_start, merge_length);
559 					merge_length = 0;
560 					instance->buf_usage = 0;
561 				}
562 			}
563 
564 			if (merge_length)
565 				usbatm_extract_cells(instance, merge_start, merge_length);
566 		} else
567 			if (!urb->status)
568 				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
569 			else
570 				instance->buf_usage = 0;
571 
572 		if (usbatm_submit_urb(urb))
573 			return;
574 	}
575 }
576 
577 
578 /***********
579 **  send  **
580 ***********/
581 
582 static void usbatm_tx_process(unsigned long data)
583 {
584 	struct usbatm_data *instance = (struct usbatm_data *)data;
585 	struct sk_buff *skb = instance->current_skb;
586 	struct urb *urb = NULL;
587 	const unsigned int buf_size = instance->tx_channel.buf_size;
588 	unsigned int bytes_written = 0;
589 	u8 *buffer = NULL;
590 
591 	if (!skb)
592 		skb = skb_dequeue(&instance->sndqueue);
593 
594 	while (skb) {
595 		if (!urb) {
596 			urb = usbatm_pop_urb(&instance->tx_channel);
597 			if (!urb)
598 				break;		/* no more senders */
599 			buffer = urb->transfer_buffer;
600 			bytes_written = (urb->status == -EAGAIN) ?
601 				urb->transfer_buffer_length : 0;
602 		}
603 
604 		bytes_written += usbatm_write_cells(instance, skb,
605 						  buffer + bytes_written,
606 						  buf_size - bytes_written);
607 
608 		vdbg(&instance->usb_intf->dev,
609 		     "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
610 		     __func__, bytes_written, skb, urb);
611 
612 		if (!UDSL_SKB(skb)->len) {
613 			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
614 
615 			usbatm_pop(vcc, skb);
616 			atomic_inc(&vcc->stats->tx);
617 
618 			skb = skb_dequeue(&instance->sndqueue);
619 		}
620 
621 		if (bytes_written == buf_size || (!skb && bytes_written)) {
622 			urb->transfer_buffer_length = bytes_written;
623 
624 			if (usbatm_submit_urb(urb))
625 				break;
626 			urb = NULL;
627 		}
628 	}
629 
630 	instance->current_skb = skb;
631 }
632 
633 static void usbatm_cancel_send(struct usbatm_data *instance,
634 			       struct atm_vcc *vcc)
635 {
636 	struct sk_buff *skb, *n;
637 
638 	spin_lock_irq(&instance->sndqueue.lock);
639 	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
640 		if (UDSL_SKB(skb)->atm.vcc == vcc) {
641 			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
642 			__skb_unlink(skb, &instance->sndqueue);
643 			usbatm_pop(vcc, skb);
644 		}
645 	}
646 	spin_unlock_irq(&instance->sndqueue.lock);
647 
648 	tasklet_disable(&instance->tx_channel.tasklet);
649 	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
650 		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
651 		instance->current_skb = NULL;
652 		usbatm_pop(vcc, skb);
653 	}
654 	tasklet_enable(&instance->tx_channel.tasklet);
655 }
656 
657 static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
658 {
659 	struct usbatm_data *instance = vcc->dev->dev_data;
660 	struct usbatm_control *ctrl = UDSL_SKB(skb);
661 	int err;
662 
663 	/* racy disconnection check - fine */
664 	if (!instance || instance->disconnected) {
665 #ifdef VERBOSE_DEBUG
666 		printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
667 #endif
668 		err = -ENODEV;
669 		goto fail;
670 	}
671 
672 	if (vcc->qos.aal != ATM_AAL5) {
673 		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
674 		err = -EINVAL;
675 		goto fail;
676 	}
677 
678 	if (skb->len > ATM_MAX_AAL5_PDU) {
679 		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
680 				__func__, skb->len, ATM_MAX_AAL5_PDU);
681 		err = -EINVAL;
682 		goto fail;
683 	}
684 
685 	PACKETDEBUG(instance, skb->data, skb->len);
686 
687 	/* initialize the control block */
688 	ctrl->atm.vcc = vcc;
689 	ctrl->len = skb->len;
690 	ctrl->crc = crc32_be(~0, skb->data, skb->len);
691 
692 	skb_queue_tail(&instance->sndqueue, skb);
693 	tasklet_schedule(&instance->tx_channel.tasklet);
694 
695 	return 0;
696 
697  fail:
698 	usbatm_pop(vcc, skb);
699 	return err;
700 }
701 
702 
703 /********************
704 **  bean counting  **
705 ********************/
706 
707 static void usbatm_destroy_instance(struct kref *kref)
708 {
709 	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
710 
711 	tasklet_kill(&instance->rx_channel.tasklet);
712 	tasklet_kill(&instance->tx_channel.tasklet);
713 	usb_put_dev(instance->usb_dev);
714 	kfree(instance);
715 }
716 
717 static void usbatm_get_instance(struct usbatm_data *instance)
718 {
719 	kref_get(&instance->refcount);
720 }
721 
722 static void usbatm_put_instance(struct usbatm_data *instance)
723 {
724 	kref_put(&instance->refcount, usbatm_destroy_instance);
725 }
726 
727 
728 /**********
729 **  ATM  **
730 **********/
731 
732 static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
733 {
734 	struct usbatm_data *instance = atm_dev->dev_data;
735 
736 	if (!instance)
737 		return;
738 
739 	atm_dev->dev_data = NULL; /* catch bugs */
740 	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
741 }
742 
743 static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
744 {
745 	struct usbatm_data *instance = atm_dev->dev_data;
746 	int left = *pos;
747 
748 	if (!instance)
749 		return -ENODEV;
750 
751 	if (!left--)
752 		return sprintf(page, "%s\n", instance->description);
753 
754 	if (!left--)
755 		return sprintf(page, "MAC: %pM\n", atm_dev->esi);
756 
757 	if (!left--)
758 		return sprintf(page,
759 			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
760 			       atomic_read(&atm_dev->stats.aal5.tx),
761 			       atomic_read(&atm_dev->stats.aal5.tx_err),
762 			       atomic_read(&atm_dev->stats.aal5.rx),
763 			       atomic_read(&atm_dev->stats.aal5.rx_err),
764 			       atomic_read(&atm_dev->stats.aal5.rx_drop));
765 
766 	if (!left--) {
767 		if (instance->disconnected)
768 			return sprintf(page, "Disconnected\n");
769 		else
770 			switch (atm_dev->signal) {
771 			case ATM_PHY_SIG_FOUND:
772 				return sprintf(page, "Line up\n");
773 			case ATM_PHY_SIG_LOST:
774 				return sprintf(page, "Line down\n");
775 			default:
776 				return sprintf(page, "Line state unknown\n");
777 			}
778 	}
779 
780 	return 0;
781 }
782 
783 static int usbatm_atm_open(struct atm_vcc *vcc)
784 {
785 	struct usbatm_data *instance = vcc->dev->dev_data;
786 	struct usbatm_vcc_data *new = NULL;
787 	int ret;
788 	int vci = vcc->vci;
789 	short vpi = vcc->vpi;
790 
791 	if (!instance)
792 		return -ENODEV;
793 
794 	/* only support AAL5 */
795 	if ((vcc->qos.aal != ATM_AAL5)) {
796 		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
797 		return -EINVAL;
798 	}
799 
800 	/* sanity checks */
801 	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
802 		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
803 		return -EINVAL;
804 	}
805 
806 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
807 
808 	if (instance->disconnected) {
809 		atm_dbg(instance, "%s: disconnected!\n", __func__);
810 		ret = -ENODEV;
811 		goto fail;
812 	}
813 
814 	if (usbatm_find_vcc(instance, vpi, vci)) {
815 		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
816 		ret = -EADDRINUSE;
817 		goto fail;
818 	}
819 
820 	new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
821 	if (!new) {
822 		ret = -ENOMEM;
823 		goto fail;
824 	}
825 
826 	new->vcc = vcc;
827 	new->vpi = vpi;
828 	new->vci = vci;
829 
830 	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
831 	if (!new->sarb) {
832 		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
833 		ret = -ENOMEM;
834 		goto fail;
835 	}
836 
837 	vcc->dev_data = new;
838 
839 	tasklet_disable(&instance->rx_channel.tasklet);
840 	instance->cached_vcc = new;
841 	instance->cached_vpi = vpi;
842 	instance->cached_vci = vci;
843 	list_add(&new->list, &instance->vcc_list);
844 	tasklet_enable(&instance->rx_channel.tasklet);
845 
846 	set_bit(ATM_VF_ADDR, &vcc->flags);
847 	set_bit(ATM_VF_PARTIAL, &vcc->flags);
848 	set_bit(ATM_VF_READY, &vcc->flags);
849 
850 	mutex_unlock(&instance->serialize);
851 
852 	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
853 
854 	return 0;
855 
856 fail:
857 	kfree(new);
858 	mutex_unlock(&instance->serialize);
859 	return ret;
860 }
861 
862 static void usbatm_atm_close(struct atm_vcc *vcc)
863 {
864 	struct usbatm_data *instance = vcc->dev->dev_data;
865 	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
866 
867 	if (!instance || !vcc_data)
868 		return;
869 
870 	usbatm_cancel_send(instance, vcc);
871 
872 	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
873 
874 	tasklet_disable(&instance->rx_channel.tasklet);
875 	if (instance->cached_vcc == vcc_data) {
876 		instance->cached_vcc = NULL;
877 		instance->cached_vpi = ATM_VPI_UNSPEC;
878 		instance->cached_vci = ATM_VCI_UNSPEC;
879 	}
880 	list_del(&vcc_data->list);
881 	tasklet_enable(&instance->rx_channel.tasklet);
882 
883 	kfree_skb(vcc_data->sarb);
884 	vcc_data->sarb = NULL;
885 
886 	kfree(vcc_data);
887 	vcc->dev_data = NULL;
888 
889 	vcc->vpi = ATM_VPI_UNSPEC;
890 	vcc->vci = ATM_VCI_UNSPEC;
891 	clear_bit(ATM_VF_READY, &vcc->flags);
892 	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
893 	clear_bit(ATM_VF_ADDR, &vcc->flags);
894 
895 	mutex_unlock(&instance->serialize);
896 }
897 
898 static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
899 			  void __user *arg)
900 {
901 	struct usbatm_data *instance = atm_dev->dev_data;
902 
903 	if (!instance || instance->disconnected)
904 		return -ENODEV;
905 
906 	switch (cmd) {
907 	case ATM_QUERYLOOP:
908 		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
909 	default:
910 		return -ENOIOCTLCMD;
911 	}
912 }
913 
914 static int usbatm_atm_init(struct usbatm_data *instance)
915 {
916 	struct atm_dev *atm_dev;
917 	int ret, i;
918 
919 	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
920 	 * condition: callbacks we register can be executed at once, before we have
921 	 * initialized the struct atm_dev.  To protect against this, all callbacks
922 	 * abort if atm_dev->dev_data is NULL. */
923 	atm_dev = atm_dev_register(instance->driver_name,
924 				   &instance->usb_intf->dev, &usbatm_atm_devops,
925 				   -1, NULL);
926 	if (!atm_dev) {
927 		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
928 		return -1;
929 	}
930 
931 	instance->atm_dev = atm_dev;
932 
933 	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
934 	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
935 	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
936 
937 	/* temp init ATM device, set to 128kbit */
938 	atm_dev->link_rate = 128 * 1000 / 424;
939 
940 	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
941 		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
942 		goto fail;
943 	}
944 
945 	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
946 
947 	/* ready for ATM callbacks */
948 	mb();
949 	atm_dev->dev_data = instance;
950 
951 	/* submit all rx URBs */
952 	for (i = 0; i < num_rcv_urbs; i++)
953 		usbatm_submit_urb(instance->urbs[i]);
954 
955 	return 0;
956 
957  fail:
958 	instance->atm_dev = NULL;
959 	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
960 	return ret;
961 }
962 
963 
964 /**********
965 **  USB  **
966 **********/
967 
968 static int usbatm_do_heavy_init(void *arg)
969 {
970 	struct usbatm_data *instance = arg;
971 	int ret;
972 
973 	allow_signal(SIGTERM);
974 	complete(&instance->thread_started);
975 
976 	ret = instance->driver->heavy_init(instance, instance->usb_intf);
977 
978 	if (!ret)
979 		ret = usbatm_atm_init(instance);
980 
981 	mutex_lock(&instance->serialize);
982 	instance->thread = NULL;
983 	mutex_unlock(&instance->serialize);
984 
985 	complete_and_exit(&instance->thread_exited, ret);
986 }
987 
988 static int usbatm_heavy_init(struct usbatm_data *instance)
989 {
990 	struct task_struct *t;
991 
992 	t = kthread_create(usbatm_do_heavy_init, instance, "%s",
993 			instance->driver->driver_name);
994 	if (IS_ERR(t)) {
995 		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
996 				__func__, PTR_ERR(t));
997 		return PTR_ERR(t);
998 	}
999 
1000 	instance->thread = t;
1001 	wake_up_process(t);
1002 	wait_for_completion(&instance->thread_started);
1003 
1004 	return 0;
1005 }
1006 
1007 static void usbatm_tasklet_schedule(unsigned long data)
1008 {
1009 	tasklet_schedule((struct tasklet_struct *) data);
1010 }
1011 
1012 static void usbatm_init_channel(struct usbatm_channel *channel)
1013 {
1014 	spin_lock_init(&channel->lock);
1015 	INIT_LIST_HEAD(&channel->list);
1016 	channel->delay.function = usbatm_tasklet_schedule;
1017 	channel->delay.data = (unsigned long) &channel->tasklet;
1018 	init_timer(&channel->delay);
1019 }
1020 
1021 int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1022 		     struct usbatm_driver *driver)
1023 {
1024 	struct device *dev = &intf->dev;
1025 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1026 	struct usbatm_data *instance;
1027 	char *buf;
1028 	int error = -ENOMEM;
1029 	int i, length;
1030 	unsigned int maxpacket, num_packets;
1031 
1032 	/* instance init */
1033 	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1034 	if (!instance)
1035 		return -ENOMEM;
1036 
1037 	/* public fields */
1038 
1039 	instance->driver = driver;
1040 	strlcpy(instance->driver_name, driver->driver_name,
1041 		sizeof(instance->driver_name));
1042 
1043 	instance->usb_dev = usb_dev;
1044 	instance->usb_intf = intf;
1045 
1046 	buf = instance->description;
1047 	length = sizeof(instance->description);
1048 
1049 	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1050 		goto bind;
1051 
1052 	buf += i;
1053 	length -= i;
1054 
1055 	i = scnprintf(buf, length, " (");
1056 	buf += i;
1057 	length -= i;
1058 
1059 	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1060 		goto bind;
1061 
1062 	buf += i;
1063 	length -= i;
1064 
1065 	snprintf(buf, length, ")");
1066 
1067  bind:
1068 	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1069 			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1070 			goto fail_free;
1071 	}
1072 
1073 	/* private fields */
1074 
1075 	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1076 	mutex_init(&instance->serialize);
1077 
1078 	instance->thread = NULL;
1079 	init_completion(&instance->thread_started);
1080 	init_completion(&instance->thread_exited);
1081 
1082 	INIT_LIST_HEAD(&instance->vcc_list);
1083 	skb_queue_head_init(&instance->sndqueue);
1084 
1085 	usbatm_init_channel(&instance->rx_channel);
1086 	usbatm_init_channel(&instance->tx_channel);
1087 	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1088 	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1089 	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1090 	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1091 	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1092 
1093 	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1094 		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1095 	else
1096 		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1097 
1098 	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1099 
1100 	/* tx buffer size must be a positive multiple of the stride */
1101 	instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1102 			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1103 
1104 	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1105 	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1106 
1107 	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1108 		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1109 				usb_pipeendpoint(instance->rx_channel.endpoint));
1110 		error = -EINVAL;
1111 		goto fail_unbind;
1112 	}
1113 
1114 	num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1115 
1116 	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1117 		num_packets--;
1118 
1119 	instance->rx_channel.buf_size = num_packets * maxpacket;
1120 	instance->rx_channel.packet_size = maxpacket;
1121 
1122 	for (i = 0; i < 2; i++) {
1123 		struct usbatm_channel *channel = i ?
1124 			&instance->tx_channel : &instance->rx_channel;
1125 
1126 		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1127 			__func__, channel->buf_size, i ? "tx" : "rx", channel);
1128 	}
1129 
1130 	/* initialize urbs */
1131 
1132 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1133 		u8 *buffer;
1134 		struct usbatm_channel *channel = i < num_rcv_urbs ?
1135 			&instance->rx_channel : &instance->tx_channel;
1136 		struct urb *urb;
1137 		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1138 
1139 		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1140 		if (!urb) {
1141 			error = -ENOMEM;
1142 			goto fail_unbind;
1143 		}
1144 
1145 		instance->urbs[i] = urb;
1146 
1147 		/* zero the tx padding to avoid leaking information */
1148 		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1149 		if (!buffer) {
1150 			error = -ENOMEM;
1151 			goto fail_unbind;
1152 		}
1153 
1154 		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1155 				  buffer, channel->buf_size, usbatm_complete, channel);
1156 		if (iso_packets) {
1157 			int j;
1158 			urb->interval = 1;
1159 			urb->transfer_flags = URB_ISO_ASAP;
1160 			urb->number_of_packets = iso_packets;
1161 			for (j = 0; j < iso_packets; j++) {
1162 				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1163 				urb->iso_frame_desc[j].length = channel->packet_size;
1164 			}
1165 		}
1166 
1167 		/* put all tx URBs on the list of spares */
1168 		if (i >= num_rcv_urbs)
1169 			list_add_tail(&urb->urb_list, &channel->list);
1170 
1171 		vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1172 		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1173 	}
1174 
1175 	instance->cached_vpi = ATM_VPI_UNSPEC;
1176 	instance->cached_vci = ATM_VCI_UNSPEC;
1177 	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1178 
1179 	if (!instance->cell_buf) {
1180 		error = -ENOMEM;
1181 		goto fail_unbind;
1182 	}
1183 
1184 	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1185 		error = usbatm_heavy_init(instance);
1186 	} else {
1187 		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1188 		error = usbatm_atm_init(instance);
1189 	}
1190 
1191 	if (error < 0)
1192 		goto fail_unbind;
1193 
1194 	usb_get_dev(usb_dev);
1195 	usb_set_intfdata(intf, instance);
1196 
1197 	return 0;
1198 
1199  fail_unbind:
1200 	if (instance->driver->unbind)
1201 		instance->driver->unbind(instance, intf);
1202  fail_free:
1203 	kfree(instance->cell_buf);
1204 
1205 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1206 		if (instance->urbs[i])
1207 			kfree(instance->urbs[i]->transfer_buffer);
1208 		usb_free_urb(instance->urbs[i]);
1209 	}
1210 
1211 	kfree(instance);
1212 
1213 	return error;
1214 }
1215 EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1216 
1217 void usbatm_usb_disconnect(struct usb_interface *intf)
1218 {
1219 	struct device *dev = &intf->dev;
1220 	struct usbatm_data *instance = usb_get_intfdata(intf);
1221 	struct usbatm_vcc_data *vcc_data;
1222 	int i;
1223 
1224 	if (!instance) {
1225 		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1226 		return;
1227 	}
1228 
1229 	usb_set_intfdata(intf, NULL);
1230 
1231 	mutex_lock(&instance->serialize);
1232 	instance->disconnected = 1;
1233 	if (instance->thread != NULL)
1234 		send_sig(SIGTERM, instance->thread, 1);
1235 	mutex_unlock(&instance->serialize);
1236 
1237 	wait_for_completion(&instance->thread_exited);
1238 
1239 	mutex_lock(&instance->serialize);
1240 	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1241 		vcc_release_async(vcc_data->vcc, -EPIPE);
1242 	mutex_unlock(&instance->serialize);
1243 
1244 	tasklet_disable(&instance->rx_channel.tasklet);
1245 	tasklet_disable(&instance->tx_channel.tasklet);
1246 
1247 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1248 		usb_kill_urb(instance->urbs[i]);
1249 
1250 	del_timer_sync(&instance->rx_channel.delay);
1251 	del_timer_sync(&instance->tx_channel.delay);
1252 
1253 	/* turn usbatm_[rt]x_process into something close to a no-op */
1254 	/* no need to take the spinlock */
1255 	INIT_LIST_HEAD(&instance->rx_channel.list);
1256 	INIT_LIST_HEAD(&instance->tx_channel.list);
1257 
1258 	tasklet_enable(&instance->rx_channel.tasklet);
1259 	tasklet_enable(&instance->tx_channel.tasklet);
1260 
1261 	if (instance->atm_dev && instance->driver->atm_stop)
1262 		instance->driver->atm_stop(instance, instance->atm_dev);
1263 
1264 	if (instance->driver->unbind)
1265 		instance->driver->unbind(instance, intf);
1266 
1267 	instance->driver_data = NULL;
1268 
1269 	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1270 		kfree(instance->urbs[i]->transfer_buffer);
1271 		usb_free_urb(instance->urbs[i]);
1272 	}
1273 
1274 	kfree(instance->cell_buf);
1275 
1276 	/* ATM finalize */
1277 	if (instance->atm_dev) {
1278 		atm_dev_deregister(instance->atm_dev);
1279 		instance->atm_dev = NULL;
1280 	}
1281 
1282 	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1283 }
1284 EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1285 
1286 
1287 /***********
1288 **  init  **
1289 ***********/
1290 
1291 static int __init usbatm_usb_init(void)
1292 {
1293 	if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1294 		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1295 		return -EIO;
1296 	}
1297 
1298 	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1299 	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1300 	    || (rcv_buf_bytes < 1)
1301 	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1302 	    || (snd_buf_bytes < 1)
1303 	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1304 		return -EINVAL;
1305 
1306 	return 0;
1307 }
1308 module_init(usbatm_usb_init);
1309 
1310 static void __exit usbatm_usb_exit(void)
1311 {
1312 }
1313 module_exit(usbatm_usb_exit);
1314 
1315 MODULE_AUTHOR(DRIVER_AUTHOR);
1316 MODULE_DESCRIPTION(DRIVER_DESC);
1317 MODULE_LICENSE("GPL");
1318 MODULE_VERSION(DRIVER_VERSION);
1319 
1320 /************
1321 **  debug  **
1322 ************/
1323 
1324 #ifdef VERBOSE_DEBUG
1325 static int usbatm_print_packet(struct usbatm_data *instance,
1326 			       const unsigned char *data, int len)
1327 {
1328 	unsigned char buffer[256];
1329 	int i = 0, j = 0;
1330 
1331 	for (i = 0; i < len;) {
1332 		buffer[0] = '\0';
1333 		sprintf(buffer, "%.3d :", i);
1334 		for (j = 0; (j < 16) && (i < len); j++, i++)
1335 			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1336 		dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1337 	}
1338 	return i;
1339 }
1340 #endif
1341