summaryrefslogtreecommitdiffstats
path: root/drivers/ata/libata-acpi.c
blob: 5ebbf16f3af1c717475213f48b204c3996cc297b (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
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
707
708
709
710
711
712
713
714
715
716
717
718
719
/*
 * libata-acpi.c
 * Provides ACPI support for PATA/SATA.
 *
 * Copyright (C) 2006 Intel Corp.
 * Copyright (C) 2006 Randy Dunlap
 */

#include <linux/ata.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/libata.h>
#include <linux/pci.h>
#include <scsi/scsi_device.h>
#include "libata.h"

#include <acpi/acpi_bus.h>
#include <acpi/acnames.h>
#include <acpi/acnamesp.h>
#include <acpi/acparser.h>
#include <acpi/acexcep.h>
#include <acpi/acmacros.h>
#include <acpi/actypes.h>

#define NO_PORT_MULT		0xffff
#define SATA_ADR(root,pmp)	(((root) << 16) | (pmp))

#define REGS_PER_GTF		7
struct ata_acpi_gtf {
	u8	tf[REGS_PER_GTF];	/* regs. 0x1f1 - 0x1f7 */
} __packed;

/*
 *	Helper - belongs in the PCI layer somewhere eventually
 */
static int is_pci_dev(struct device *dev)
{
	return (dev->bus == &pci_bus_type);
}

/**
 * ata_acpi_associate_sata_port - associate SATA port with ACPI objects
 * @ap: target SATA port
 *
 * Look up ACPI objects associated with @ap and initialize acpi_handle
 * fields of @ap, the port and devices accordingly.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
void ata_acpi_associate_sata_port(struct ata_port *ap)
{
	WARN_ON(!(ap->flags & ATA_FLAG_ACPI_SATA));

	if (!ap->nr_pmp_links) {
		acpi_integer adr = SATA_ADR(ap->port_no, NO_PORT_MULT);

		ap->link.device->acpi_handle =
			acpi_get_child(ap->host->acpi_handle, adr);
	} else {
		struct ata_link *link;

		ap->link.device->acpi_handle = NULL;

		ata_port_for_each_link(link, ap) {
			acpi_integer adr = SATA_ADR(ap->port_no, link->pmp);

			link->device->acpi_handle =
				acpi_get_child(ap->host->acpi_handle, adr);
		}
	}
}

static void ata_acpi_associate_ide_port(struct ata_port *ap)
{
	int max_devices, i;

	ap->acpi_handle = acpi_get_child(ap->host->acpi_handle, ap->port_no);
	if (!ap->acpi_handle)
		return;

	max_devices = 1;
	if (ap->flags & ATA_FLAG_SLAVE_POSS)
		max_devices++;

	for (i = 0; i < max_devices; i++) {
		struct ata_device *dev = &ap->link.device[i];

		dev->acpi_handle = acpi_get_child(ap->acpi_handle, i);
	}
}

static void ata_acpi_handle_hotplug (struct ata_port *ap, struct kobject *kobj,
				     u32 event)
{
	char event_string[12];
	char *envp[] = { event_string, NULL };
	struct ata_eh_info *ehi = &ap->link.eh_info;

	if (event == 0 || event == 1) {
	       unsigned long flags;
	       spin_lock_irqsave(ap->lock, flags);
	       ata_ehi_clear_desc(ehi);
	       ata_ehi_push_desc(ehi, "ACPI event");
	       ata_ehi_hotplugged(ehi);
	       ata_port_freeze(ap);
	       spin_unlock_irqrestore(ap->lock, flags);
	}

	if (kobj) {
	        sprintf(event_string, "BAY_EVENT=%d", event);
		kobject_uevent_env(kobj, KOBJ_CHANGE, envp);
	}
}

static void ata_acpi_dev_notify(acpi_handle handle, u32 event, void *data)
{
	struct ata_device *dev = data;
	struct kobject *kobj = NULL;

	if (dev->sdev)
		kobj = &dev->sdev->sdev_gendev.kobj;

	ata_acpi_handle_hotplug (dev->link->ap, kobj, event);
}

static void ata_acpi_ap_notify(acpi_handle handle, u32 event, void *data)
{
	struct ata_port *ap = data;

	ata_acpi_handle_hotplug (ap, &ap->dev->kobj, event);
}

/**
 * ata_acpi_associate - associate ATA host with ACPI objects
 * @host: target ATA host
 *
 * Look up ACPI objects associated with @host and initialize
 * acpi_handle fields of @host, its ports and devices accordingly.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
void ata_acpi_associate(struct ata_host *host)
{
	int i, j;

	if (!is_pci_dev(host->dev) || libata_noacpi)
		return;

	host->acpi_handle = DEVICE_ACPI_HANDLE(host->dev);
	if (!host->acpi_handle)
		return;

	for (i = 0; i < host->n_ports; i++) {
		struct ata_port *ap = host->ports[i];

		if (host->ports[0]->flags & ATA_FLAG_ACPI_SATA)
			ata_acpi_associate_sata_port(ap);
		else
			ata_acpi_associate_ide_port(ap);

		if (ap->acpi_handle)
			acpi_install_notify_handler (ap->acpi_handle,
						     ACPI_SYSTEM_NOTIFY,
						     ata_acpi_ap_notify,
						     ap);

		for (j = 0; j < ata_link_max_devices(&ap->link); j++) {
			struct ata_device *dev = &ap->link.device[j];

			if (dev->acpi_handle)
				acpi_install_notify_handler (dev->acpi_handle,
							     ACPI_SYSTEM_NOTIFY,
							     ata_acpi_dev_notify,
							     dev);
		}
	}
}

/**
 * ata_acpi_gtm - execute _GTM
 * @ap: target ATA port
 * @gtm: out parameter for _GTM result
 *
 * Evaluate _GTM and store the result in @gtm.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
 */
static int ata_acpi_gtm(const struct ata_port *ap, struct ata_acpi_gtm *gtm)
{
	struct acpi_buffer output = { .length = ACPI_ALLOCATE_BUFFER };
	union acpi_object *out_obj;
	acpi_status status;
	int rc = 0;

	status = acpi_evaluate_object(ap->acpi_handle, "_GTM", NULL, &output);

	rc = -ENOENT;
	if (status == AE_NOT_FOUND)
		goto out_free;

	rc = -EINVAL;
	if (ACPI_FAILURE(status)) {
		ata_port_printk(ap, KERN_ERR,
				"ACPI get timing mode failed (AE 0x%x)\n",
				status);
		goto out_free;
	}

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
		ata_port_printk(ap, KERN_WARNING,
				"_GTM returned unexpected object type 0x%x\n",
				out_obj->type);

		goto out_free;
	}

	if (out_obj->buffer.length != sizeof(struct ata_acpi_gtm)) {
		ata_port_printk(ap, KERN_ERR,
				"_GTM returned invalid length %d\n",
				out_obj->buffer.length);
		goto out_free;
	}

	memcpy(gtm, out_obj->buffer.pointer, sizeof(struct ata_acpi_gtm));
	rc = 0;
 out_free:
	kfree(output.pointer);
	return rc;
}

/**
 * ata_acpi_stm - execute _STM
 * @ap: target ATA port
 * @stm: timing parameter to _STM
 *
 * Evaluate _STM with timing parameter @stm.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -ENOENT if _STM doesn't exist, -errno on failure.
 */
static int ata_acpi_stm(const struct ata_port *ap, struct ata_acpi_gtm *stm)
{
	acpi_status status;
	struct acpi_object_list         input;
	union acpi_object               in_params[3];

	in_params[0].type = ACPI_TYPE_BUFFER;
	in_params[0].buffer.length = sizeof(struct ata_acpi_gtm);
	in_params[0].buffer.pointer = (u8 *)stm;
	/* Buffers for id may need byteswapping ? */
	in_params[1].type = ACPI_TYPE_BUFFER;
	in_params[1].buffer.length = 512;
	in_params[1].buffer.pointer = (u8 *)ap->link.device[0].id;
	in_params[2].type = ACPI_TYPE_BUFFER;
	in_params[2].buffer.length = 512;
	in_params[2].buffer.pointer = (u8 *)ap->link.device[1].id;

	input.count = 3;
	input.pointer = in_params;

	status = acpi_evaluate_object(ap->acpi_handle, "_STM", &input, NULL);

	if (status == AE_NOT_FOUND)
		return -ENOENT;
	if (ACPI_FAILURE(status)) {
		ata_port_printk(ap, KERN_ERR,
			"ACPI set timing mode failed (status=0x%x)\n", status);
		return -EINVAL;
	}
	return 0;
}

/**
 * ata_dev_get_GTF - get the drive bootup default taskfile settings
 * @dev: target ATA device
 * @gtf: output parameter for buffer containing _GTF taskfile arrays
 * @ptr_to_free: pointer which should be freed
 *
 * This applies to both PATA and SATA drives.
 *
 * The _GTF method has no input parameters.
 * It returns a variable number of register set values (registers
 * hex 1F1..1F7, taskfiles).
 * The <variable number> is not known in advance, so have ACPI-CA
 * allocate the buffer as needed and return it, then free it later.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * Number of taskfiles on success, 0 if _GTF doesn't exist or doesn't
 * contain valid data.  -errno on other errors.
 */
static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf,
			   void **ptr_to_free)
{
	struct ata_port *ap = dev->link->ap;
	acpi_status status;
	struct acpi_buffer output;
	union acpi_object *out_obj;
	int rc = 0;

	/* set up output buffer */
	output.length = ACPI_ALLOCATE_BUFFER;
	output.pointer = NULL;	/* ACPI-CA sets this; save/free it later */

	if (ata_msg_probe(ap))
		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER: port#: %d\n",
			       __FUNCTION__, ap->port_no);

	/* _GTF has no input parameters */
	status = acpi_evaluate_object(dev->acpi_handle, "_GTF", NULL, &output);

	if (ACPI_FAILURE(status)) {
		if (status != AE_NOT_FOUND) {
			ata_dev_printk(dev, KERN_WARNING,
				       "_GTF evaluation failed (AE 0x%x)\n",
				       status);
			rc = -EIO;
		}
		goto out_free;
	}

	if (!output.length || !output.pointer) {
		if (ata_msg_probe(ap))
			ata_dev_printk(dev, KERN_DEBUG, "%s: Run _GTF: "
				"length or ptr is NULL (0x%llx, 0x%p)\n",
				__FUNCTION__,
				(unsigned long long)output.length,
				output.pointer);
		goto out_free;
	}

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
		ata_dev_printk(dev, KERN_WARNING,
			       "_GTF unexpected object type 0x%x\n",
			       out_obj->type);
		rc = -EINVAL;
		goto out_free;
	}

	if (out_obj->buffer.length % REGS_PER_GTF) {
		ata_dev_printk(dev, KERN_WARNING,
			       "unexpected _GTF length (%d)\n",
			       out_obj->buffer.length);
		rc = -EINVAL;
		goto out_free;
	}

	*ptr_to_free = out_obj;
	*gtf = (void *)out_obj->buffer.pointer;
	rc = out_obj->buffer.length / REGS_PER_GTF;

	if (ata_msg_probe(ap))
		ata_dev_printk(dev, KERN_DEBUG, "%s: returning "
			"gtf=%p, gtf_count=%d, ptr_to_free=%p\n",
			__FUNCTION__, *gtf, rc, *ptr_to_free);
	return rc;

 out_free:
	kfree(output.pointer);
	return rc;
}

/**
 * ata_acpi_cbl_80wire		-	Check for 80 wire cable
 * @ap: Port to check
 *
 * Return 1 if the ACPI mode data for this port indicates the BIOS selected
 * an 80wire mode.
 */

int ata_acpi_cbl_80wire(struct ata_port *ap)
{
	struct ata_acpi_gtm gtm;
	int valid = 0;
	
	/* No _GTM data, no information */
	if (ata_acpi_gtm(ap, &gtm) < 0)
		return 0;
		
	/* Split timing, DMA enabled */
	if ((gtm.flags & 0x11) == 0x11 && gtm.drive[0].dma < 55)
		valid |= 1;
	if ((gtm.flags & 0x14) == 0x14 && gtm.drive[1].dma < 55)
		valid |= 2;
	/* Shared timing, DMA enabled */
	if ((gtm.flags & 0x11) == 0x01 && gtm.drive[0].dma < 55)
		valid |= 1;
	if ((gtm.flags & 0x14) == 0x04 && gtm.drive[0].dma < 55)
		valid |= 2;

	/* Drive check */
	if ((valid & 1) && ata_dev_enabled(&ap->link.device[0]))
		return 1;
	if ((valid & 2) && ata_dev_enabled(&ap->link.device[1]))
		return 1;
	return 0;
}

EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);

/**
 * taskfile_load_raw - send taskfile registers to host controller
 * @dev: target ATA device
 * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
 *
 * Outputs ATA taskfile to standard ATA host controller using MMIO
 * or PIO as indicated by the ATA_FLAG_MMIO flag.
 * Writes the control, feature, nsect, lbal, lbam, and lbah registers.
 * Optionally (ATA_TFLAG_LBA48) writes hob_feature, hob_nsect,
 * hob_lbal, hob_lbam, and hob_lbah.
 *
 * This function waits for idle (!BUSY and !DRQ) after writing
 * registers.  If the control register has a new value, this
 * function also waits for idle after writing control and before
 * writing the remaining registers.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
static int taskfile_load_raw(struct ata_device *dev,
			      const struct ata_acpi_gtf *gtf)
{
	struct ata_port *ap = dev->link->ap;
	struct ata_taskfile tf, rtf;
	unsigned int err_mask;

	if ((gtf->tf[0] == 0) && (gtf->tf[1] == 0) && (gtf->tf[2] == 0)
	    && (gtf->tf[3] == 0) && (gtf->tf[4] == 0) && (gtf->tf[5] == 0)
	    && (gtf->tf[6] == 0))
		return 0;

	ata_tf_init(dev, &tf);

	/* convert gtf to tf */
	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; /* TBD */
	tf.protocol = ATA_PROT_NODATA;
	tf.feature = gtf->tf[0];	/* 0x1f1 */
	tf.nsect   = gtf->tf[1];	/* 0x1f2 */
	tf.lbal    = gtf->tf[2];	/* 0x1f3 */
	tf.lbam    = gtf->tf[3];	/* 0x1f4 */
	tf.lbah    = gtf->tf[4];	/* 0x1f5 */
	tf.device  = gtf->tf[5];	/* 0x1f6 */
	tf.command = gtf->tf[6];	/* 0x1f7 */

	if (ata_msg_probe(ap))
		ata_dev_printk(dev, KERN_DEBUG, "executing ACPI cmd "
			       "%02x/%02x:%02x:%02x:%02x:%02x:%02x\n",
			       tf.command, tf.feature, tf.nsect,
			       tf.lbal, tf.lbam, tf.lbah, tf.device);

	rtf = tf;
	err_mask = ata_exec_internal(dev, &rtf, NULL, DMA_NONE, NULL, 0);
	if (err_mask) {
		ata_dev_printk(dev, KERN_ERR,
			"ACPI cmd %02x/%02x:%02x:%02x:%02x:%02x:%02x failed "
			"(Emask=0x%x Stat=0x%02x Err=0x%02x)\n",
			tf.command, tf.feature, tf.nsect, tf.lbal, tf.lbam,
			tf.lbah, tf.device, err_mask, rtf.command, rtf.feature);
		return -EIO;
	}

	return 0;
}

/**
 * ata_acpi_exec_tfs - get then write drive taskfile settings
 * @dev: target ATA device
 *
 * Evaluate _GTF and excute returned taskfiles.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * Number of executed taskfiles on success, 0 if _GTF doesn't exist or
 * doesn't contain valid data.  -errno on other errors.
 */
static int ata_acpi_exec_tfs(struct ata_device *dev)
{
	struct ata_acpi_gtf *gtf = NULL;
	void *ptr_to_free = NULL;
	int gtf_count, i, rc;

	/* get taskfiles */
	rc = ata_dev_get_GTF(dev, &gtf, &ptr_to_free);
	if (rc < 0)
		return rc;
	gtf_count = rc;

	/* execute them */
	for (i = 0, rc = 0; i < gtf_count; i++) {
		int tmp;

		/* ACPI errors are eventually ignored.  Run till the
		 * end even after errors.
		 */
		tmp = taskfile_load_raw(dev, gtf++);
		if (!rc)
			rc = tmp;
	}

	kfree(ptr_to_free);

	if (rc == 0)
		return gtf_count;
	return rc;
}

/**
 * ata_acpi_push_id - send Identify data to drive
 * @dev: target ATA device
 *
 * _SDD ACPI object: for SATA mode only
 * Must be after Identify (Packet) Device -- uses its data
 * ATM this function never returns a failure.  It is an optional
 * method and if it fails for whatever reason, we should still
 * just keep going.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
static int ata_acpi_push_id(struct ata_device *dev)
{
	struct ata_port *ap = dev->link->ap;
	int err;
	acpi_status status;
	struct acpi_object_list input;
	union acpi_object in_params[1];

	if (ata_msg_probe(ap))
		ata_dev_printk(dev, KERN_DEBUG, "%s: ix = %d, port#: %d\n",
			       __FUNCTION__, dev->devno, ap->port_no);

	/* Give the drive Identify data to the drive via the _SDD method */
	/* _SDD: set up input parameters */
	input.count = 1;
	input.pointer = in_params;
	in_params[0].type = ACPI_TYPE_BUFFER;
	in_params[0].buffer.length = sizeof(dev->id[0]) * ATA_ID_WORDS;
	in_params[0].buffer.pointer = (u8 *)dev->id;
	/* Output buffer: _SDD has no output */

	/* It's OK for _SDD to be missing too. */
	swap_buf_le16(dev->id, ATA_ID_WORDS);
	status = acpi_evaluate_object(dev->acpi_handle, "_SDD", &input, NULL);
	swap_buf_le16(dev->id, ATA_ID_WORDS);

	err = ACPI_FAILURE(status) ? -EIO : 0;
	if (err < 0)
		ata_dev_printk(dev, KERN_WARNING,
			       "ACPI _SDD failed (AE 0x%x)\n", status);

	return err;
}

/**
 * ata_acpi_on_suspend - ATA ACPI hook called on suspend
 * @ap: target ATA port
 *
 * This function is called when @ap is about to be suspended.  All
 * devices are already put to sleep but the port_suspend() callback
 * hasn't been executed yet.  Error return from this function aborts
 * suspend.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int ata_acpi_on_suspend(struct ata_port *ap)
{
	unsigned long flags;
	int rc;

	/* proceed iff per-port acpi_handle is valid */
	if (!ap->acpi_handle)
		return 0;
	BUG_ON(ap->flags & ATA_FLAG_ACPI_SATA);

	/* store timing parameters */
	rc = ata_acpi_gtm(ap, &ap->acpi_gtm);

	spin_lock_irqsave(ap->lock, flags);
	if (rc == 0)
		ap->pflags |= ATA_PFLAG_GTM_VALID;
	else
		ap->pflags &= ~ATA_PFLAG_GTM_VALID;
	spin_unlock_irqrestore(ap->lock, flags);

	if (rc == -ENOENT)
		rc = 0;
	return rc;
}

/**
 * ata_acpi_on_resume - ATA ACPI hook called on resume
 * @ap: target ATA port
 *
 * This function is called when @ap is resumed - right after port
 * itself is resumed but before any EH action is taken.
 *
 * LOCKING:
 * EH context.
 */
void ata_acpi_on_resume(struct ata_port *ap)
{
	struct ata_device *dev;

	if (ap->acpi_handle && (ap->pflags & ATA_PFLAG_GTM_VALID)) {
		BUG_ON(ap->flags & ATA_FLAG_ACPI_SATA);

		/* restore timing parameters */
		ata_acpi_stm(ap, &ap->acpi_gtm);
	}

	/* schedule _GTF */
	ata_link_for_each_dev(dev, &ap->link)
		dev->flags |= ATA_DFLAG_ACPI_PENDING;
}

/**
 * ata_acpi_on_devcfg - ATA ACPI hook called on device donfiguration
 * @dev: target ATA device
 *
 * This function is called when @dev is about to be configured.
 * IDENTIFY data might have been modified after this hook is run.
 *
 * LOCKING:
 * EH context.
 *
 * RETURNS:
 * Positive number if IDENTIFY data needs to be refreshed, 0 if not,
 * -errno on failure.
 */
int ata_acpi_on_devcfg(struct ata_device *dev)
{
	struct ata_port *ap = dev->link->ap;
	struct ata_eh_context *ehc = &ap->link.eh_context;
	int acpi_sata = ap->flags & ATA_FLAG_ACPI_SATA;
	int rc;

	if (!dev->acpi_handle)
		return 0;

	/* do we need to do _GTF? */
	if (!(dev->flags & ATA_DFLAG_ACPI_PENDING) &&
	    !(acpi_sata && (ehc->i.flags & ATA_EHI_DID_HARDRESET)))
		return 0;

	/* do _SDD if SATA */
	if (acpi_sata) {
		rc = ata_acpi_push_id(dev);
		if (rc)
			goto acpi_err;
	}

	/* do _GTF */
	rc = ata_acpi_exec_tfs(dev);
	if (rc < 0)
		goto acpi_err;

	dev->flags &= ~ATA_DFLAG_ACPI_PENDING;

	/* refresh IDENTIFY page if any _GTF command has been executed */
	if (rc > 0) {
		rc = ata_dev_reread_id(dev, 0);
		if (rc < 0) {
			ata_dev_printk(dev, KERN_ERR, "failed to IDENTIFY "
				       "after ACPI commands\n");
			return rc;
		}
	}

	return 0;

 acpi_err:
	/* let EH retry on the first failure, disable ACPI on the second */
	if (dev->flags & ATA_DFLAG_ACPI_FAILED) {
		ata_dev_printk(dev, KERN_WARNING, "ACPI on devcfg failed the "
			       "second time, disabling (errno=%d)\n", rc);

		dev->acpi_handle = NULL;

		/* if port is working, request IDENTIFY reload and continue */
		if (!(ap->pflags & ATA_PFLAG_FROZEN))
			rc = 1;
	}
	dev->flags |= ATA_DFLAG_ACPI_FAILED;
	return rc;
}