summaryrefslogtreecommitdiffstats
path: root/drivers/misc/mei/init.c
blob: 49600d6e37265976b31ab80231aacaa6dcea914f (plain)
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
/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 */

#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>

#include "mei_dev.h"
#include "hw.h"
#include "interface.h"
#include <linux/mei.h>

const char *mei_dev_state_str(int state)
{
#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
	switch (state) {
	MEI_DEV_STATE(INITIALIZING);
	MEI_DEV_STATE(INIT_CLIENTS);
	MEI_DEV_STATE(ENABLED);
	MEI_DEV_STATE(RESETING);
	MEI_DEV_STATE(DISABLED);
	MEI_DEV_STATE(RECOVERING_FROM_RESET);
	MEI_DEV_STATE(POWER_DOWN);
	MEI_DEV_STATE(POWER_UP);
	default:
		return "unkown";
	}
#undef MEI_DEV_STATE
}



/**
 * mei_io_list_flush - removes list entry belonging to cl.
 *
 * @list:  An instance of our list structure
 * @cl: private data of the file object
 */
void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
{
	struct mei_cl_cb *pos;
	struct mei_cl_cb *next;

	list_for_each_entry_safe(pos, next, &list->list, list) {
		if (pos->cl) {
			if (mei_cl_cmp_id(cl, pos->cl))
				list_del(&pos->list);
		}
	}
}
/**
 * mei_cl_flush_queues - flushes queue lists belonging to cl.
 *
 * @dev: the device structure
 * @cl: private data of the file object
 */
int mei_cl_flush_queues(struct mei_cl *cl)
{
	if (!cl || !cl->dev)
		return -EINVAL;

	dev_dbg(&cl->dev->pdev->dev, "remove list entry belonging to cl\n");
	mei_io_list_flush(&cl->dev->read_list, cl);
	mei_io_list_flush(&cl->dev->write_list, cl);
	mei_io_list_flush(&cl->dev->write_waiting_list, cl);
	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
	mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
	return 0;
}



/**
 * init_mei_device - allocates and initializes the mei device structure
 *
 * @pdev: The pci device structure
 *
 * returns The mei_device_device pointer on success, NULL on failure.
 */
struct mei_device *mei_device_init(struct pci_dev *pdev)
{
	struct mei_device *dev;

	dev = kzalloc(sizeof(struct mei_device), GFP_KERNEL);
	if (!dev)
		return NULL;

	/* setup our list array */
	INIT_LIST_HEAD(&dev->file_list);
	INIT_LIST_HEAD(&dev->wd_cl.link);
	INIT_LIST_HEAD(&dev->iamthif_cl.link);
	mutex_init(&dev->device_lock);
	init_waitqueue_head(&dev->wait_recvd_msg);
	init_waitqueue_head(&dev->wait_stop_wd);
	dev->dev_state = MEI_DEV_INITIALIZING;
	dev->iamthif_state = MEI_IAMTHIF_IDLE;

	mei_io_list_init(&dev->read_list);
	mei_io_list_init(&dev->write_list);
	mei_io_list_init(&dev->write_waiting_list);
	mei_io_list_init(&dev->ctrl_wr_list);
	mei_io_list_init(&dev->ctrl_rd_list);
	mei_io_list_init(&dev->amthif_cmd_list);
	mei_io_list_init(&dev->amthif_rd_complete_list);
	dev->pdev = pdev;
	return dev;
}

/**
 * mei_hw_init - initializes host and fw to start work.
 *
 * @dev: the device structure
 *
 * returns 0 on success, <0 on failure.
 */
int mei_hw_init(struct mei_device *dev)
{
	int err = 0;
	int ret;

	mutex_lock(&dev->device_lock);

	dev->host_hw_state = mei_hcsr_read(dev);
	dev->me_hw_state = mei_mecsr_read(dev);
	dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, mestate = 0x%08x.\n",
	    dev->host_hw_state, dev->me_hw_state);

	/* acknowledge interrupt and stop interupts */
	if ((dev->host_hw_state & H_IS) == H_IS)
		mei_reg_write(dev, H_CSR, dev->host_hw_state);

	/* Doesn't change in runtime */
	dev->hbuf_depth = (dev->host_hw_state & H_CBD) >> 24;

	dev->recvd_msg = false;
	dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");

	mei_reset(dev, 1);

	dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
	    dev->host_hw_state, dev->me_hw_state);

	/* wait for ME to turn on ME_RDY */
	if (!dev->recvd_msg) {
		mutex_unlock(&dev->device_lock);
		err = wait_event_interruptible_timeout(dev->wait_recvd_msg,
			dev->recvd_msg,
			mei_secs_to_jiffies(MEI_INTEROP_TIMEOUT));
		mutex_lock(&dev->device_lock);
	}

	if (err <= 0 && !dev->recvd_msg) {
		dev->dev_state = MEI_DEV_DISABLED;
		dev_dbg(&dev->pdev->dev,
			"wait_event_interruptible_timeout failed"
			"on wait for ME to turn on ME_RDY.\n");
		ret = -ENODEV;
		goto out;
	}

	if (!(((dev->host_hw_state & H_RDY) == H_RDY) &&
	      ((dev->me_hw_state & ME_RDY_HRA) == ME_RDY_HRA))) {
		dev->dev_state = MEI_DEV_DISABLED;
		dev_dbg(&dev->pdev->dev,
			"host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
			dev->host_hw_state, dev->me_hw_state);

		if (!(dev->host_hw_state & H_RDY))
			dev_dbg(&dev->pdev->dev, "host turn off H_RDY.\n");

		if (!(dev->me_hw_state & ME_RDY_HRA))
			dev_dbg(&dev->pdev->dev, "ME turn off ME_RDY.\n");

		dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
		ret = -ENODEV;
		goto out;
	}

	if (dev->version.major_version != HBM_MAJOR_VERSION ||
	    dev->version.minor_version != HBM_MINOR_VERSION) {
		dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
		ret = -ENODEV;
		goto out;
	}

	dev->recvd_msg = false;
	dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
	    dev->host_hw_state, dev->me_hw_state);
	dev_dbg(&dev->pdev->dev, "ME turn on ME_RDY and host turn on H_RDY.\n");
	dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
	dev_dbg(&dev->pdev->dev, "MEI  start success.\n");
	ret = 0;

out:
	mutex_unlock(&dev->device_lock);
	return ret;
}

/**
 * mei_hw_reset - resets fw via mei csr register.
 *
 * @dev: the device structure
 * @interrupts_enabled: if interrupt should be enabled after reset.
 */
static void mei_hw_reset(struct mei_device *dev, int interrupts_enabled)
{
	dev->host_hw_state |= (H_RST | H_IG);

	if (interrupts_enabled)
		mei_enable_interrupts(dev);
	else
		mei_disable_interrupts(dev);
}

/**
 * mei_reset - resets host and fw.
 *
 * @dev: the device structure
 * @interrupts_enabled: if interrupt should be enabled after reset.
 */
void mei_reset(struct mei_device *dev, int interrupts_enabled)
{
	struct mei_cl *cl_pos = NULL;
	struct mei_cl *cl_next = NULL;
	struct mei_cl_cb *cb_pos = NULL;
	struct mei_cl_cb *cb_next = NULL;
	bool unexpected;

	if (dev->dev_state == MEI_DEV_RECOVERING_FROM_RESET) {
		dev->need_reset = true;
		return;
	}

	unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
			dev->dev_state != MEI_DEV_DISABLED &&
			dev->dev_state != MEI_DEV_POWER_DOWN &&
			dev->dev_state != MEI_DEV_POWER_UP);

	dev->host_hw_state = mei_hcsr_read(dev);

	dev_dbg(&dev->pdev->dev, "before reset host_hw_state = 0x%08x.\n",
	    dev->host_hw_state);

	mei_hw_reset(dev, interrupts_enabled);

	dev->host_hw_state &= ~H_RST;
	dev->host_hw_state |= H_IG;

	mei_hcsr_set(dev);

	dev_dbg(&dev->pdev->dev, "currently saved host_hw_state = 0x%08x.\n",
	    dev->host_hw_state);

	dev->need_reset = false;

	if (dev->dev_state != MEI_DEV_INITIALIZING) {
		if (dev->dev_state != MEI_DEV_DISABLED &&
		    dev->dev_state != MEI_DEV_POWER_DOWN)
			dev->dev_state = MEI_DEV_RESETING;

		list_for_each_entry_safe(cl_pos,
				cl_next, &dev->file_list, link) {
			cl_pos->state = MEI_FILE_DISCONNECTED;
			cl_pos->mei_flow_ctrl_creds = 0;
			cl_pos->read_cb = NULL;
			cl_pos->timer_count = 0;
		}
		/* remove entry if already in list */
		dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
		mei_me_cl_unlink(dev, &dev->wd_cl);

		mei_me_cl_unlink(dev, &dev->iamthif_cl);

		mei_amthif_reset_params(dev);
		memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
	}

	dev->me_clients_num = 0;
	dev->rd_msg_hdr = 0;
	dev->wd_pending = false;

	/* update the state of the registers after reset */
	dev->host_hw_state = mei_hcsr_read(dev);
	dev->me_hw_state = mei_mecsr_read(dev);

	dev_dbg(&dev->pdev->dev, "after reset host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
	    dev->host_hw_state, dev->me_hw_state);

	if (unexpected)
		dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
			 mei_dev_state_str(dev->dev_state));

	/* Wake up all readings so they can be interrupted */
	list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
		if (waitqueue_active(&cl_pos->rx_wait)) {
			dev_dbg(&dev->pdev->dev, "Waking up client!\n");
			wake_up_interruptible(&cl_pos->rx_wait);
		}
	}
	/* remove all waiting requests */
	list_for_each_entry_safe(cb_pos, cb_next, &dev->write_list.list, list) {
		list_del(&cb_pos->list);
		mei_io_cb_free(cb_pos);
	}
}



/**
 * host_start_message - mei host sends start message.
 *
 * @dev: the device structure
 *
 * returns none.
 */
void mei_host_start_message(struct mei_device *dev)
{
	struct mei_msg_hdr *mei_hdr;
	struct hbm_host_version_request *start_req;
	const size_t len = sizeof(struct hbm_host_version_request);

	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);

	/* host start message */
	start_req = (struct hbm_host_version_request *)&dev->wr_msg_buf[1];
	memset(start_req, 0, len);
	start_req->hbm_cmd = HOST_START_REQ_CMD;
	start_req->host_version.major_version = HBM_MAJOR_VERSION;
	start_req->host_version.minor_version = HBM_MINOR_VERSION;

	dev->recvd_msg = false;
	if (mei_write_message(dev, mei_hdr, (unsigned char *)start_req, len)) {
		dev_dbg(&dev->pdev->dev, "write send version message to FW fail.\n");
		dev->dev_state = MEI_DEV_RESETING;
		mei_reset(dev, 1);
	}
	dev->init_clients_state = MEI_START_MESSAGE;
	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
	return ;
}

/**
 * host_enum_clients_message - host sends enumeration client request message.
 *
 * @dev: the device structure
 *
 * returns none.
 */
void mei_host_enum_clients_message(struct mei_device *dev)
{
	struct mei_msg_hdr *mei_hdr;
	struct hbm_host_enum_request *enum_req;
	const size_t len = sizeof(struct hbm_host_enum_request);
	/* enumerate clients */
	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);

	enum_req = (struct hbm_host_enum_request *) &dev->wr_msg_buf[1];
	memset(enum_req, 0, sizeof(struct hbm_host_enum_request));
	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;

	if (mei_write_message(dev, mei_hdr, (unsigned char *)enum_req, len)) {
		dev->dev_state = MEI_DEV_RESETING;
		dev_dbg(&dev->pdev->dev, "write send enumeration request message to FW fail.\n");
		mei_reset(dev, 1);
	}
	dev->init_clients_state = MEI_ENUM_CLIENTS_MESSAGE;
	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
	return;
}


/**
 * allocate_me_clients_storage - allocates storage for me clients
 *
 * @dev: the device structure
 *
 * returns none.
 */
void mei_allocate_me_clients_storage(struct mei_device *dev)
{
	struct mei_me_client *clients;
	int b;

	/* count how many ME clients we have */
	for_each_set_bit(b, dev->me_clients_map, MEI_CLIENTS_MAX)
		dev->me_clients_num++;

	if (dev->me_clients_num <= 0)
		return ;


	if (dev->me_clients != NULL) {
		kfree(dev->me_clients);
		dev->me_clients = NULL;
	}
	dev_dbg(&dev->pdev->dev, "memory allocation for ME clients size=%zd.\n",
		dev->me_clients_num * sizeof(struct mei_me_client));
	/* allocate storage for ME clients representation */
	clients = kcalloc(dev->me_clients_num,
			sizeof(struct mei_me_client), GFP_KERNEL);
	if (!clients) {
		dev_dbg(&dev->pdev->dev, "memory allocation for ME clients failed.\n");
		dev->dev_state = MEI_DEV_RESETING;
		mei_reset(dev, 1);
		return ;
	}
	dev->me_clients = clients;
	return ;
}
/**
 * host_client_properties - reads properties for client
 *
 * @dev: the device structure
 *
 * returns:
 * 	< 0 - Error.
 *  = 0 - no more clients.
 *  = 1 - still have clients to send properties request.
 */
int mei_host_client_properties(struct mei_device *dev)
{

	struct mei_msg_hdr *mei_hdr;
	struct hbm_props_request *prop_req;
	const size_t len = sizeof(struct hbm_props_request);

	int b;
	u8 client_num = dev->me_client_presentation_num;

	prop_req = (struct hbm_props_request *)&dev->wr_msg_buf[1];

	b = dev->me_client_index;
	b = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, b);
	if (b < MEI_CLIENTS_MAX) {
		dev->me_clients[client_num].client_id = b;
		dev->me_clients[client_num].mei_flow_ctrl_creds = 0;
		mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);


		memset(prop_req, 0, sizeof(struct hbm_props_request));

		prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
		prop_req->address = b;

		if (mei_write_message(dev, mei_hdr,
				(unsigned char *)prop_req, len)) {
			dev->dev_state = MEI_DEV_RESETING;
			dev_dbg(&dev->pdev->dev, "write send enumeration request message to FW fail.\n");
			mei_reset(dev, 1);
			return -EIO;
		}

		dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
		dev->me_client_index = b;
		return 1;
	}

	return 0;
}

/**
 * mei_init_file_private - initializes private file structure.
 *
 * @priv: private file structure to be initialized
 * @file: the file structure
 */
void mei_cl_init(struct mei_cl *priv, struct mei_device *dev)
{
	memset(priv, 0, sizeof(struct mei_cl));
	init_waitqueue_head(&priv->wait);
	init_waitqueue_head(&priv->rx_wait);
	init_waitqueue_head(&priv->tx_wait);
	INIT_LIST_HEAD(&priv->link);
	priv->reading_state = MEI_IDLE;
	priv->writing_state = MEI_IDLE;
	priv->dev = dev;
}

int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *cuuid)
{
	int i, res = -ENOENT;

	for (i = 0; i < dev->me_clients_num; ++i)
		if (uuid_le_cmp(*cuuid,
				dev->me_clients[i].props.protocol_name) == 0) {
			res = i;
			break;
		}

	return res;
}


/**
 * mei_me_cl_link - create link between host and me clinet and add
 *   me_cl to the list
 *
 * @dev: the device structure
 * @cl: link between me and host client assocated with opened file descriptor
 * @cuuid: uuid of ME client
 * @client_id: id of the host client
 *
 * returns ME client index if ME client
 *	-EINVAL on incorrect values
 *	-ENONET if client not found
 */
int mei_me_cl_link(struct mei_device *dev, struct mei_cl *cl,
			const uuid_le *cuuid, u8 host_cl_id)
{
	int i;

	if (!dev || !cl || !cuuid)
		return -EINVAL;

	/* check for valid client id */
	i = mei_me_cl_by_uuid(dev, cuuid);
	if (i >= 0) {
		cl->me_client_id = dev->me_clients[i].client_id;
		cl->state = MEI_FILE_CONNECTING;
		cl->host_client_id = host_cl_id;

		list_add_tail(&cl->link, &dev->file_list);
		return (u8)i;
	}

	return -ENOENT;
}
/**
 * mei_me_cl_unlink - remove me_cl from the list
 *
 * @dev: the device structure
 * @host_client_id: host client id to be removed
 */
void mei_me_cl_unlink(struct mei_device *dev, struct mei_cl *cl)
{
	struct mei_cl *pos, *next;
	list_for_each_entry_safe(pos, next, &dev->file_list, link) {
		if (cl->host_client_id == pos->host_client_id) {
			dev_dbg(&dev->pdev->dev, "remove host client = %d, ME client = %d\n",
					pos->host_client_id, pos->me_client_id);
			list_del_init(&pos->link);
			break;
		}
	}
}

/**
 * mei_alloc_file_private - allocates a private file structure and sets it up.
 * @file: the file structure
 *
 * returns  The allocated file or NULL on failure
 */
struct mei_cl *mei_cl_allocate(struct mei_device *dev)
{
	struct mei_cl *cl;

	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
	if (!cl)
		return NULL;

	mei_cl_init(cl, dev);

	return cl;
}



/**
 * mei_disconnect_host_client - sends disconnect message to fw from host client.
 *
 * @dev: the device structure
 * @cl: private data of the file object
 *
 * Locking: called under "dev->device_lock" lock
 *
 * returns 0 on success, <0 on failure.
 */
int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl)
{
	struct mei_cl_cb *cb;
	int rets, err;

	if (!dev || !cl)
		return -ENODEV;

	if (cl->state != MEI_FILE_DISCONNECTING)
		return 0;

	cb = mei_io_cb_init(cl, NULL);
	if (!cb)
		return -ENOMEM;

	cb->fop_type = MEI_FOP_CLOSE;
	if (dev->mei_host_buffer_is_empty) {
		dev->mei_host_buffer_is_empty = false;
		if (mei_disconnect(dev, cl)) {
			rets = -ENODEV;
			dev_dbg(&dev->pdev->dev, "failed to call mei_disconnect.\n");
			goto free;
		}
		mdelay(10); /* Wait for hardware disconnection ready */
		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
	} else {
		dev_dbg(&dev->pdev->dev, "add disconnect cb to control write list\n");
		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);

	}
	mutex_unlock(&dev->device_lock);

	err = wait_event_timeout(dev->wait_recvd_msg,
			MEI_FILE_DISCONNECTED == cl->state,
			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));

	mutex_lock(&dev->device_lock);
	if (MEI_FILE_DISCONNECTED == cl->state) {
		rets = 0;
		dev_dbg(&dev->pdev->dev, "successfully disconnected from FW client.\n");
	} else {
		rets = -ENODEV;
		if (MEI_FILE_DISCONNECTED != cl->state)
			dev_dbg(&dev->pdev->dev, "wrong status client disconnect.\n");

		if (err)
			dev_dbg(&dev->pdev->dev,
					"wait failed disconnect err=%08x\n",
					err);

		dev_dbg(&dev->pdev->dev, "failed to disconnect from FW client.\n");
	}

	mei_io_list_flush(&dev->ctrl_rd_list, cl);
	mei_io_list_flush(&dev->ctrl_wr_list, cl);
free:
	mei_io_cb_free(cb);
	return rets;
}