core-card.c 19.5 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706
/*
 * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
 *
 * 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.
 */

#include <linux/bug.h>
#include <linux/completion.h>
#include <linux/crc-itu-t.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>

#include <linux/atomic.h>
#include <asm/byteorder.h>

#include "core.h"

#define define_fw_printk_level(func, kern_level)		\
void func(const struct fw_card *card, const char *fmt, ...)	\
{								\
	struct va_format vaf;					\
	va_list args;						\
								\
	va_start(args, fmt);					\
	vaf.fmt = fmt;						\
	vaf.va = &args;						\
	printk(kern_level KBUILD_MODNAME " %s: %pV",		\
	       dev_name(card->device), &vaf);			\
	va_end(args);						\
}
define_fw_printk_level(fw_err, KERN_ERR);
define_fw_printk_level(fw_notice, KERN_NOTICE);

int fw_compute_block_crc(__be32 *block)
{
	int length;
	u16 crc;

	length = (be32_to_cpu(block[0]) >> 16) & 0xff;
	crc = crc_itu_t(0, (u8 *)&block[1], length * 4);
	*block |= cpu_to_be32(crc);

	return length;
}

static DEFINE_MUTEX(card_mutex);
static LIST_HEAD(card_list);

static LIST_HEAD(descriptor_list);
static int descriptor_count;

static __be32 tmp_config_rom[256];
/* ROM header, bus info block, root dir header, capabilities = 7 quadlets */
static size_t config_rom_length = 1 + 4 + 1 + 1;

#define BIB_CRC(v)		((v) <<  0)
#define BIB_CRC_LENGTH(v)	((v) << 16)
#define BIB_INFO_LENGTH(v)	((v) << 24)
#define BIB_BUS_NAME		0x31333934 /* "1394" */
#define BIB_LINK_SPEED(v)	((v) <<  0)
#define BIB_GENERATION(v)	((v) <<  4)
#define BIB_MAX_ROM(v)		((v) <<  8)
#define BIB_MAX_RECEIVE(v)	((v) << 12)
#define BIB_CYC_CLK_ACC(v)	((v) << 16)
#define BIB_PMC			((1) << 27)
#define BIB_BMC			((1) << 28)
#define BIB_ISC			((1) << 29)
#define BIB_CMC			((1) << 30)
#define BIB_IRMC		((1) << 31)
#define NODE_CAPABILITIES	0x0c0083c0 /* per IEEE 1394 clause 8.3.2.6.5.2 */

/*
 * IEEE-1394 specifies a default SPLIT_TIMEOUT value of 800 cycles (100 ms),
 * but we have to make it longer because there are many devices whose firmware
 * is just too slow for that.
 */
#define DEFAULT_SPLIT_TIMEOUT	(2 * 8000)

#define CANON_OUI		0x000085

static void generate_config_rom(struct fw_card *card, __be32 *config_rom)
{
	struct fw_descriptor *desc;
	int i, j, k, length;

	/*
	 * Initialize contents of config rom buffer.  On the OHCI
	 * controller, block reads to the config rom accesses the host
	 * memory, but quadlet read access the hardware bus info block
	 * registers.  That's just crack, but it means we should make
	 * sure the contents of bus info block in host memory matches
	 * the version stored in the OHCI registers.
	 */

	config_rom[0] = cpu_to_be32(
		BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0));
	config_rom[1] = cpu_to_be32(BIB_BUS_NAME);
	config_rom[2] = cpu_to_be32(
		BIB_LINK_SPEED(card->link_speed) |
		BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
		BIB_MAX_ROM(2) |
		BIB_MAX_RECEIVE(card->max_receive) |
		BIB_BMC | BIB_ISC | BIB_CMC | BIB_IRMC);
	config_rom[3] = cpu_to_be32(card->guid >> 32);
	config_rom[4] = cpu_to_be32(card->guid);

	/* Generate root directory. */
	config_rom[6] = cpu_to_be32(NODE_CAPABILITIES);
	i = 7;
	j = 7 + descriptor_count;

	/* Generate root directory entries for descriptors. */
	list_for_each_entry (desc, &descriptor_list, link) {
		if (desc->immediate > 0)
			config_rom[i++] = cpu_to_be32(desc->immediate);
		config_rom[i] = cpu_to_be32(desc->key | (j - i));
		i++;
		j += desc->length;
	}

	/* Update root directory length. */
	config_rom[5] = cpu_to_be32((i - 5 - 1) << 16);

	/* End of root directory, now copy in descriptors. */
	list_for_each_entry (desc, &descriptor_list, link) {
		for (k = 0; k < desc->length; k++)
			config_rom[i + k] = cpu_to_be32(desc->data[k]);
		i += desc->length;
	}

	/* Calculate CRCs for all blocks in the config rom.  This
	 * assumes that CRC length and info length are identical for
	 * the bus info block, which is always the case for this
	 * implementation. */
	for (i = 0; i < j; i += length + 1)
		length = fw_compute_block_crc(config_rom + i);

	WARN_ON(j != config_rom_length);
}

static void update_config_roms(void)
{
	struct fw_card *card;

	list_for_each_entry (card, &card_list, link) {
		generate_config_rom(card, tmp_config_rom);
		card->driver->set_config_rom(card, tmp_config_rom,
					     config_rom_length);
	}
}

static size_t required_space(struct fw_descriptor *desc)
{
	/* descriptor + entry into root dir + optional immediate entry */
	return desc->length + 1 + (desc->immediate > 0 ? 1 : 0);
}

int fw_core_add_descriptor(struct fw_descriptor *desc)
{
	size_t i;
	int ret;

	/*
	 * Check descriptor is valid; the length of all blocks in the
	 * descriptor has to add up to exactly the length of the
	 * block.
	 */
	i = 0;
	while (i < desc->length)
		i += (desc->data[i] >> 16) + 1;

	if (i != desc->length)
		return -EINVAL;

	mutex_lock(&card_mutex);

	if (config_rom_length + required_space(desc) > 256) {
		ret = -EBUSY;
	} else {
		list_add_tail(&desc->link, &descriptor_list);
		config_rom_length += required_space(desc);
		descriptor_count++;
		if (desc->immediate > 0)
			descriptor_count++;
		update_config_roms();
		ret = 0;
	}

	mutex_unlock(&card_mutex);

	return ret;
}
EXPORT_SYMBOL(fw_core_add_descriptor);

void fw_core_remove_descriptor(struct fw_descriptor *desc)
{
	mutex_lock(&card_mutex);

	list_del(&desc->link);
	config_rom_length -= required_space(desc);
	descriptor_count--;
	if (desc->immediate > 0)
		descriptor_count--;
	update_config_roms();

	mutex_unlock(&card_mutex);
}
EXPORT_SYMBOL(fw_core_remove_descriptor);

static int reset_bus(struct fw_card *card, bool short_reset)
{
	int reg = short_reset ? 5 : 1;
	int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;

	return card->driver->update_phy_reg(card, reg, 0, bit);
}

void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset)
{
	/* We don't try hard to sort out requests of long vs. short resets. */
	card->br_short = short_reset;

	/* Use an arbitrary short delay to combine multiple reset requests. */
	fw_card_get(card);
	if (!queue_delayed_work(fw_workqueue, &card->br_work,
				delayed ? DIV_ROUND_UP(HZ, 100) : 0))
		fw_card_put(card);
}
EXPORT_SYMBOL(fw_schedule_bus_reset);

static void br_work(struct work_struct *work)
{
	struct fw_card *card = container_of(work, struct fw_card, br_work.work);

	/* Delay for 2s after last reset per IEEE 1394 clause 8.2.1. */
	if (card->reset_jiffies != 0 &&
	    time_before64(get_jiffies_64(), card->reset_jiffies + 2 * HZ)) {
		if (!queue_delayed_work(fw_workqueue, &card->br_work, 2 * HZ))
			fw_card_put(card);
		return;
	}

	fw_send_phy_config(card, FW_PHY_CONFIG_NO_NODE_ID, card->generation,
			   FW_PHY_CONFIG_CURRENT_GAP_COUNT);
	reset_bus(card, card->br_short);
	fw_card_put(card);
}

static void allocate_broadcast_channel(struct fw_card *card, int generation)
{
	int channel, bandwidth = 0;

	if (!card->broadcast_channel_allocated) {
		fw_iso_resource_manage(card, generation, 1ULL << 31,
				       &channel, &bandwidth, true);
		if (channel != 31) {
			fw_notice(card, "failed to allocate broadcast channel\n");
			return;
		}
		card->broadcast_channel_allocated = true;
	}

	device_for_each_child(card->device, (void *)(long)generation,
			      fw_device_set_broadcast_channel);
}

static const char gap_count_table[] = {
	63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
};

void fw_schedule_bm_work(struct fw_card *card, unsigned long delay)
{
	fw_card_get(card);
	if (!schedule_delayed_work(&card->bm_work, delay))
		fw_card_put(card);
}

static void bm_work(struct work_struct *work)
{
	struct fw_card *card = container_of(work, struct fw_card, bm_work.work);
	struct fw_device *root_device, *irm_device;
	struct fw_node *root_node;
	int root_id, new_root_id, irm_id, bm_id, local_id;
	int gap_count, generation, grace, rcode;
	bool do_reset = false;
	bool root_device_is_running;
	bool root_device_is_cmc;
	bool irm_is_1394_1995_only;
	bool keep_this_irm;
	__be32 transaction_data[2];

	spin_lock_irq(&card->lock);

	if (card->local_node == NULL) {
		spin_unlock_irq(&card->lock);
		goto out_put_card;
	}

	generation = card->generation;

	root_node = card->root_node;
	fw_node_get(root_node);
	root_device = root_node->data;
	root_device_is_running = root_device &&
			atomic_read(&root_device->state) == FW_DEVICE_RUNNING;
	root_device_is_cmc = root_device && root_device->cmc;

	irm_device = card->irm_node->data;
	irm_is_1394_1995_only = irm_device && irm_device->config_rom &&
			(irm_device->config_rom[2] & 0x000000f0) == 0;

	/* Canon MV5i works unreliably if it is not root node. */
	keep_this_irm = irm_device && irm_device->config_rom &&
			irm_device->config_rom[3] >> 8 == CANON_OUI;

	root_id  = root_node->node_id;
	irm_id   = card->irm_node->node_id;
	local_id = card->local_node->node_id;

	grace = time_after64(get_jiffies_64(),
			     card->reset_jiffies + DIV_ROUND_UP(HZ, 8));

	if ((is_next_generation(generation, card->bm_generation) &&
	     !card->bm_abdicate) ||
	    (card->bm_generation != generation && grace)) {
		/*
		 * This first step is to figure out who is IRM and
		 * then try to become bus manager.  If the IRM is not
		 * well defined (e.g. does not have an active link
		 * layer or does not responds to our lock request, we
		 * will have to do a little vigilante bus management.
		 * In that case, we do a goto into the gap count logic
		 * so that when we do the reset, we still optimize the
		 * gap count.  That could well save a reset in the
		 * next generation.
		 */

		if (!card->irm_node->link_on) {
			new_root_id = local_id;
			fw_notice(card, "%s, making local node (%02x) root\n",
				  "IRM has link off", new_root_id);
			goto pick_me;
		}

		if (irm_is_1394_1995_only && !keep_this_irm) {
			new_root_id = local_id;
			fw_notice(card, "%s, making local node (%02x) root\n",
				  "IRM is not 1394a compliant", new_root_id);
			goto pick_me;
		}

		transaction_data[0] = cpu_to_be32(0x3f);
		transaction_data[1] = cpu_to_be32(local_id);

		spin_unlock_irq(&card->lock);

		rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
				irm_id, generation, SCODE_100,
				CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
				transaction_data, 8);

		if (rcode == RCODE_GENERATION)
			/* Another bus reset, BM work has been rescheduled. */
			goto out;

		bm_id = be32_to_cpu(transaction_data[0]);

		spin_lock_irq(&card->lock);
		if (rcode == RCODE_COMPLETE && generation == card->generation)
			card->bm_node_id =
			    bm_id == 0x3f ? local_id : 0xffc0 | bm_id;
		spin_unlock_irq(&card->lock);

		if (rcode == RCODE_COMPLETE && bm_id != 0x3f) {
			/* Somebody else is BM.  Only act as IRM. */
			if (local_id == irm_id)
				allocate_broadcast_channel(card, generation);

			goto out;
		}

		if (rcode == RCODE_SEND_ERROR) {
			/*
			 * We have been unable to send the lock request due to
			 * some local problem.  Let's try again later and hope
			 * that the problem has gone away by then.
			 */
			fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8));
			goto out;
		}

		spin_lock_irq(&card->lock);

		if (rcode != RCODE_COMPLETE && !keep_this_irm) {
			/*
			 * The lock request failed, maybe the IRM
			 * isn't really IRM capable after all. Let's
			 * do a bus reset and pick the local node as
			 * root, and thus, IRM.
			 */
			new_root_id = local_id;
			fw_notice(card, "BM lock failed (%s), making local node (%02x) root\n",
				  fw_rcode_string(rcode), new_root_id);
			goto pick_me;
		}
	} else if (card->bm_generation != generation) {
		/*
		 * We weren't BM in the last generation, and the last
		 * bus reset is less than 125ms ago.  Reschedule this job.
		 */
		spin_unlock_irq(&card->lock);
		fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8));
		goto out;
	}

	/*
	 * We're bus manager for this generation, so next step is to
	 * make sure we have an active cycle master and do gap count
	 * optimization.
	 */
	card->bm_generation = generation;

	if (root_device == NULL) {
		/*
		 * Either link_on is false, or we failed to read the
		 * config rom.  In either case, pick another root.
		 */
		new_root_id = local_id;
	} else if (!root_device_is_running) {
		/*
		 * If we haven't probed this device yet, bail out now
		 * and let's try again once that's done.
		 */
		spin_unlock_irq(&card->lock);
		goto out;
	} else if (root_device_is_cmc) {
		/*
		 * We will send out a force root packet for this
		 * node as part of the gap count optimization.
		 */
		new_root_id = root_id;
	} else {
		/*
		 * Current root has an active link layer and we
		 * successfully read the config rom, but it's not
		 * cycle master capable.
		 */
		new_root_id = local_id;
	}

 pick_me:
	/*
	 * Pick a gap count from 1394a table E-1.  The table doesn't cover
	 * the typically much larger 1394b beta repeater delays though.
	 */
	if (!card->beta_repeaters_present &&
	    root_node->max_hops < ARRAY_SIZE(gap_count_table))
		gap_count = gap_count_table[root_node->max_hops];
	else
		gap_count = 63;

	/*
	 * Finally, figure out if we should do a reset or not.  If we have
	 * done less than 5 resets with the same physical topology and we
	 * have either a new root or a new gap count setting, let's do it.
	 */

	if (card->bm_retries++ < 5 &&
	    (card->gap_count != gap_count || new_root_id != root_id))
		do_reset = true;

	spin_unlock_irq(&card->lock);

	if (do_reset) {
		fw_notice(card, "phy config: new root=%x, gap_count=%d\n",
			  new_root_id, gap_count);
		fw_send_phy_config(card, new_root_id, generation, gap_count);
		reset_bus(card, true);
		/* Will allocate broadcast channel after the reset. */
		goto out;
	}

	if (root_device_is_cmc) {
		/*
		 * Make sure that the cycle master sends cycle start packets.
		 */
		transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
		rcode = fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
				root_id, generation, SCODE_100,
				CSR_REGISTER_BASE + CSR_STATE_SET,
				transaction_data, 4);
		if (rcode == RCODE_GENERATION)
			goto out;
	}

	if (local_id == irm_id)
		allocate_broadcast_channel(card, generation);

 out:
	fw_node_put(root_node);
 out_put_card:
	fw_card_put(card);
}

void fw_card_initialize(struct fw_card *card,
			const struct fw_card_driver *driver,
			struct device *device)
{
	static atomic_t index = ATOMIC_INIT(-1);

	card->index = atomic_inc_return(&index);
	card->driver = driver;
	card->device = device;
	card->current_tlabel = 0;
	card->tlabel_mask = 0;
	card->split_timeout_hi = DEFAULT_SPLIT_TIMEOUT / 8000;
	card->split_timeout_lo = (DEFAULT_SPLIT_TIMEOUT % 8000) << 19;
	card->split_timeout_cycles = DEFAULT_SPLIT_TIMEOUT;
	card->split_timeout_jiffies =
			DIV_ROUND_UP(DEFAULT_SPLIT_TIMEOUT * HZ, 8000);
	card->color = 0;
	card->broadcast_channel = BROADCAST_CHANNEL_INITIAL;

	kref_init(&card->kref);
	init_completion(&card->done);
	INIT_LIST_HEAD(&card->transaction_list);
	INIT_LIST_HEAD(&card->phy_receiver_list);
	spin_lock_init(&card->lock);

	card->local_node = NULL;

	INIT_DELAYED_WORK(&card->br_work, br_work);
	INIT_DELAYED_WORK(&card->bm_work, bm_work);
}
EXPORT_SYMBOL(fw_card_initialize);

int fw_card_add(struct fw_card *card,
		u32 max_receive, u32 link_speed, u64 guid)
{
	int ret;

	card->max_receive = max_receive;
	card->link_speed = link_speed;
	card->guid = guid;

	mutex_lock(&card_mutex);

	generate_config_rom(card, tmp_config_rom);
	ret = card->driver->enable(card, tmp_config_rom, config_rom_length);
	if (ret == 0)
		list_add_tail(&card->link, &card_list);

	mutex_unlock(&card_mutex);

	return ret;
}
EXPORT_SYMBOL(fw_card_add);

/*
 * The next few functions implement a dummy driver that is used once a card
 * driver shuts down an fw_card.  This allows the driver to cleanly unload,
 * as all IO to the card will be handled (and failed) by the dummy driver
 * instead of calling into the module.  Only functions for iso context
 * shutdown still need to be provided by the card driver.
 *
 * .read/write_csr() should never be called anymore after the dummy driver
 * was bound since they are only used within request handler context.
 * .set_config_rom() is never called since the card is taken out of card_list
 * before switching to the dummy driver.
 */

static int dummy_read_phy_reg(struct fw_card *card, int address)
{
	return -ENODEV;
}

static int dummy_update_phy_reg(struct fw_card *card, int address,
				int clear_bits, int set_bits)
{
	return -ENODEV;
}

static void dummy_send_request(struct fw_card *card, struct fw_packet *packet)
{
	packet->callback(packet, card, RCODE_CANCELLED);
}

static void dummy_send_response(struct fw_card *card, struct fw_packet *packet)
{
	packet->callback(packet, card, RCODE_CANCELLED);
}

static int dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
{
	return -ENOENT;
}

static int dummy_enable_phys_dma(struct fw_card *card,
				 int node_id, int generation)
{
	return -ENODEV;
}

static struct fw_iso_context *dummy_allocate_iso_context(struct fw_card *card,
				int type, int channel, size_t header_size)
{
	return ERR_PTR(-ENODEV);
}

static int dummy_start_iso(struct fw_iso_context *ctx,
			   s32 cycle, u32 sync, u32 tags)
{
	return -ENODEV;
}

static int dummy_set_iso_channels(struct fw_iso_context *ctx, u64 *channels)
{
	return -ENODEV;
}

static int dummy_queue_iso(struct fw_iso_context *ctx, struct fw_iso_packet *p,
			   struct fw_iso_buffer *buffer, unsigned long payload)
{
	return -ENODEV;
}

static void dummy_flush_queue_iso(struct fw_iso_context *ctx)
{
}

static int dummy_flush_iso_completions(struct fw_iso_context *ctx)
{
	return -ENODEV;
}

static const struct fw_card_driver dummy_driver_template = {
	.read_phy_reg		= dummy_read_phy_reg,
	.update_phy_reg		= dummy_update_phy_reg,
	.send_request		= dummy_send_request,
	.send_response		= dummy_send_response,
	.cancel_packet		= dummy_cancel_packet,
	.enable_phys_dma	= dummy_enable_phys_dma,
	.allocate_iso_context	= dummy_allocate_iso_context,
	.start_iso		= dummy_start_iso,
	.set_iso_channels	= dummy_set_iso_channels,
	.queue_iso		= dummy_queue_iso,
	.flush_queue_iso	= dummy_flush_queue_iso,
	.flush_iso_completions	= dummy_flush_iso_completions,
};

void fw_card_release(struct kref *kref)
{
	struct fw_card *card = container_of(kref, struct fw_card, kref);

	complete(&card->done);
}
EXPORT_SYMBOL_GPL(fw_card_release);

void fw_core_remove_card(struct fw_card *card)
{
	struct fw_card_driver dummy_driver = dummy_driver_template;

	card->driver->update_phy_reg(card, 4,
				     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
	fw_schedule_bus_reset(card, false, true);

	mutex_lock(&card_mutex);
	list_del_init(&card->link);
	mutex_unlock(&card_mutex);

	/* Switch off most of the card driver interface. */
	dummy_driver.free_iso_context	= card->driver->free_iso_context;
	dummy_driver.stop_iso		= card->driver->stop_iso;
	card->driver = &dummy_driver;

	fw_destroy_nodes(card);

	/* Wait for all users, especially device workqueue jobs, to finish. */
	fw_card_put(card);
	wait_for_completion(&card->done);

	WARN_ON(!list_empty(&card->transaction_list));
}
EXPORT_SYMBOL(fw_core_remove_card);