2 * Support for SATA devices on Serial Attached SCSI (SAS) controllers
4 * Copyright (C) 2006 IBM Corporation
6 * Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
24 #include <linux/scatterlist.h>
25 #include <linux/slab.h>
27 #include <scsi/sas_ata.h>
28 #include "sas_internal.h"
29 #include <scsi/scsi_host.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_tcq.h>
32 #include <scsi/scsi.h>
33 #include <scsi/scsi_transport.h>
34 #include <scsi/scsi_transport_sas.h>
35 #include "../scsi_sas_internal.h"
36 #include "../scsi_transport_api.h"
37 #include <scsi/scsi_eh.h>
39 static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
41 /* Cheesy attempt to translate SAS errors into ATA. Hah! */
44 if (ts->resp == SAS_TASK_UNDELIVERED)
45 return AC_ERR_ATA_BUS;
47 /* ts->resp == SAS_TASK_COMPLETE */
48 /* task delivered, what happened afterwards? */
50 case SAS_DEV_NO_RESPONSE:
51 return AC_ERR_TIMEOUT;
56 return AC_ERR_ATA_BUS;
59 case SAS_DATA_UNDERRUN:
61 * Some programs that use the taskfile interface
62 * (smartctl in particular) can cause underrun
63 * problems. Ignore these errors, perhaps at our
68 case SAS_DATA_OVERRUN:
70 case SAS_DEVICE_UNKNOWN:
72 return AC_ERR_INVALID;
76 SAS_DPRINTK("%s: Saw error %d. What to do?\n",
80 case SAM_STAT_CHECK_CONDITION:
81 case SAS_ABORTED_TASK:
84 case SAS_PROTO_RESPONSE:
85 /* This means the ending_fis has the error
86 * value; return 0 here to collect it */
93 static void sas_ata_task_done(struct sas_task *task)
95 struct ata_queued_cmd *qc = task->uldd_task;
96 struct domain_device *dev;
97 struct task_status_struct *stat = &task->task_status;
98 struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
99 struct sas_ha_struct *sas_ha;
100 enum ata_completion_errors ac;
102 struct ata_link *link;
105 goto qc_already_gone;
107 dev = qc->ap->private_data;
108 sas_ha = dev->port->ha;
109 link = &dev->sata_dev.ap->link;
111 spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
112 if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_STAT_GOOD ||
113 ((stat->stat == SAM_STAT_CHECK_CONDITION &&
114 dev->sata_dev.command_set == ATAPI_COMMAND_SET))) {
115 ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
117 if (!link->sactive) {
118 qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
120 link->eh_info.err_mask |= ac_err_mask(dev->sata_dev.tf.command);
121 if (unlikely(link->eh_info.err_mask))
122 qc->flags |= ATA_QCFLAG_FAILED;
125 dev->sata_dev.sstatus = resp->sstatus;
126 dev->sata_dev.serror = resp->serror;
127 dev->sata_dev.scontrol = resp->scontrol;
129 ac = sas_to_ata_err(stat);
131 SAS_DPRINTK("%s: SAS error %x\n", __func__,
133 /* We saw a SAS error. Send a vague error. */
134 if (!link->sactive) {
137 link->eh_info.err_mask |= AC_ERR_DEV;
138 qc->flags |= ATA_QCFLAG_FAILED;
141 dev->sata_dev.tf.feature = 0x04; /* status err */
142 dev->sata_dev.tf.command = ATA_ERR;
146 qc->lldd_task = NULL;
148 ASSIGN_SAS_TASK(qc->scsicmd, NULL);
150 spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
153 * If the sas_task has an ata qc, a scsi_cmnd and the aborted
154 * flag is set, then we must have come in via the libsas EH
155 * functions. When we exit this function, we need to put the
156 * scsi_cmnd on the list of finished errors. The ata_qc_complete
157 * call cleans up the libata side of things but we're protected
158 * from the scsi_cmnd going away because the scsi_cmnd is owned
159 * by the EH, making libata's call to scsi_done a NOP.
161 spin_lock_irqsave(&task->task_state_lock, flags);
162 if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
163 scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
164 spin_unlock_irqrestore(&task->task_state_lock, flags);
167 list_del_init(&task->list);
171 static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
174 struct sas_task *task;
175 struct domain_device *dev = qc->ap->private_data;
176 struct sas_ha_struct *sas_ha = dev->port->ha;
177 struct Scsi_Host *host = sas_ha->core.shost;
178 struct sas_internal *i = to_sas_internal(host->transportt);
179 struct scatterlist *sg;
180 unsigned int xfer = 0;
183 /* If the device fell off, no sense in issuing commands */
185 return AC_ERR_SYSTEM;
187 task = sas_alloc_task(GFP_ATOMIC);
189 return AC_ERR_SYSTEM;
191 task->task_proto = SAS_PROTOCOL_STP;
192 task->task_done = sas_ata_task_done;
194 if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
195 qc->tf.command == ATA_CMD_FPDMA_READ) {
196 /* Need to zero out the tag libata assigned us */
200 ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
201 task->uldd_task = qc;
202 if (ata_is_atapi(qc->tf.protocol)) {
203 memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
204 task->total_xfer_len = qc->nbytes;
205 task->num_scatter = qc->n_elem;
207 for_each_sg(qc->sg, sg, qc->n_elem, si)
210 task->total_xfer_len = xfer;
211 task->num_scatter = si;
214 task->data_dir = qc->dma_dir;
215 task->scatter = qc->sg;
216 task->ata_task.retry_count = 1;
217 task->task_state_flags = SAS_TASK_STATE_PENDING;
218 qc->lldd_task = task;
220 switch (qc->tf.protocol) {
222 task->ata_task.use_ncq = 1;
226 task->ata_task.dma_xfer = 1;
231 ASSIGN_SAS_TASK(qc->scsicmd, task);
233 if (sas_ha->lldd_max_execute_num < 2)
234 res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
236 res = sas_queue_up(task);
240 SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
243 ASSIGN_SAS_TASK(qc->scsicmd, NULL);
245 return AC_ERR_SYSTEM;
251 static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
253 struct domain_device *dev = qc->ap->private_data;
255 memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
259 static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
260 unsigned long deadline)
262 struct ata_port *ap = link->ap;
263 struct domain_device *dev = ap->private_data;
264 struct sas_internal *i =
265 to_sas_internal(dev->port->ha->core.shost->transportt);
266 int res = TMF_RESP_FUNC_FAILED;
269 if (i->dft->lldd_I_T_nexus_reset)
270 res = i->dft->lldd_I_T_nexus_reset(dev);
272 if (res != TMF_RESP_FUNC_COMPLETE) {
273 SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);
277 switch (dev->sata_dev.command_set) {
278 case ATA_COMMAND_SET:
279 SAS_DPRINTK("%s: Found ATA device.\n", __func__);
280 *class = ATA_DEV_ATA;
282 case ATAPI_COMMAND_SET:
283 SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
284 *class = ATA_DEV_ATAPI;
287 SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
289 dev->sata_dev.command_set);
290 *class = ATA_DEV_UNKNOWN;
294 ap->cbl = ATA_CBL_SATA;
298 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
300 if (qc->flags & ATA_QCFLAG_FAILED)
301 qc->err_mask |= AC_ERR_OTHER;
305 * Find the sas_task and kill it. By this point,
306 * libata has decided to kill the qc, so we needn't
307 * bother with sas_ata_task_done. But we still
308 * ought to abort the task.
310 struct sas_task *task = qc->lldd_task;
313 qc->lldd_task = NULL;
315 /* Should this be a AT(API) device reset? */
316 spin_lock_irqsave(&task->task_state_lock, flags);
317 task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
318 spin_unlock_irqrestore(&task->task_state_lock, flags);
320 task->uldd_task = NULL;
321 __sas_task_abort(task);
326 static struct ata_port_operations sas_sata_ops = {
327 .prereset = ata_std_prereset,
329 .hardreset = sas_ata_hard_reset,
330 .postreset = ata_std_postreset,
331 .error_handler = ata_std_error_handler,
332 .post_internal_cmd = sas_ata_post_internal,
333 .qc_defer = ata_std_qc_defer,
334 .qc_prep = ata_noop_qc_prep,
335 .qc_issue = sas_ata_qc_issue,
336 .qc_fill_rtf = sas_ata_qc_fill_rtf,
337 .port_start = ata_sas_port_start,
338 .port_stop = ata_sas_port_stop,
341 static struct ata_port_info sata_port_info = {
342 .flags = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
343 .pio_mask = ATA_PIO4,
344 .mwdma_mask = ATA_MWDMA2,
345 .udma_mask = ATA_UDMA6,
346 .port_ops = &sas_sata_ops
349 int sas_ata_init_host_and_port(struct domain_device *found_dev,
350 struct scsi_target *starget)
352 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
353 struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
356 ata_host_init(&found_dev->sata_dev.ata_host,
358 sata_port_info.flags,
360 ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
364 SAS_DPRINTK("ata_sas_port_alloc failed.\n");
368 ap->private_data = found_dev;
369 ap->cbl = ATA_CBL_SATA;
370 ap->scsi_host = shost;
371 found_dev->sata_dev.ap = ap;
376 void sas_ata_task_abort(struct sas_task *task)
378 struct ata_queued_cmd *qc = task->uldd_task;
379 struct completion *waiting;
381 /* Bounce SCSI-initiated commands to the SCSI EH */
383 struct request_queue *q = qc->scsicmd->device->request_queue;
386 spin_lock_irqsave(q->queue_lock, flags);
387 blk_abort_request(qc->scsicmd->request);
388 spin_unlock_irqrestore(q->queue_lock, flags);
389 scsi_schedule_eh(qc->scsicmd->device->host);
393 /* Internal command, fake a timeout and complete. */
394 qc->flags &= ~ATA_QCFLAG_ACTIVE;
395 qc->flags |= ATA_QCFLAG_FAILED;
396 qc->err_mask |= AC_ERR_TIMEOUT;
397 waiting = qc->private_data;
401 static void sas_task_timedout(unsigned long _task)
403 struct sas_task *task = (void *) _task;
406 spin_lock_irqsave(&task->task_state_lock, flags);
407 if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
408 task->task_state_flags |= SAS_TASK_STATE_ABORTED;
409 spin_unlock_irqrestore(&task->task_state_lock, flags);
411 complete(&task->completion);
414 static void sas_disc_task_done(struct sas_task *task)
416 if (!del_timer(&task->timer))
418 complete(&task->completion);
421 #define SAS_DEV_TIMEOUT 10
424 * sas_execute_task -- Basic task processing for discovery
425 * @task: the task to be executed
426 * @buffer: pointer to buffer to do I/O
427 * @size: size of @buffer
428 * @dma_dir: DMA direction. DMA_xxx
430 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
431 enum dma_data_direction dma_dir)
434 struct scatterlist *scatter = NULL;
435 struct task_status_struct *ts = &task->task_status;
438 struct sas_internal *i =
439 to_sas_internal(task->dev->port->ha->core.shost->transportt);
441 if (dma_dir != DMA_NONE) {
442 scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
446 sg_init_one(scatter, buffer, size);
450 task->task_proto = task->dev->tproto;
451 task->scatter = scatter;
452 task->num_scatter = num_scatter;
453 task->total_xfer_len = size;
454 task->data_dir = dma_dir;
455 task->task_done = sas_disc_task_done;
456 if (dma_dir != DMA_NONE &&
457 sas_protocol_ata(task->task_proto)) {
458 task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
464 for (retries = 0; retries < 5; retries++) {
465 task->task_state_flags = SAS_TASK_STATE_PENDING;
466 init_completion(&task->completion);
468 task->timer.data = (unsigned long) task;
469 task->timer.function = sas_task_timedout;
470 task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
471 add_timer(&task->timer);
473 res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
475 del_timer(&task->timer);
476 SAS_DPRINTK("executing SAS discovery task failed:%d\n",
480 wait_for_completion(&task->completion);
482 if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
484 SAS_DPRINTK("task aborted, flags:0x%x\n",
485 task->task_state_flags);
486 res2 = i->dft->lldd_abort_task(task);
487 SAS_DPRINTK("came back from abort task\n");
488 if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
489 if (res2 == TMF_RESP_FUNC_COMPLETE)
490 continue; /* Retry the task */
495 if (task->task_status.stat == SAM_STAT_BUSY ||
496 task->task_status.stat == SAM_STAT_TASK_SET_FULL ||
497 task->task_status.stat == SAS_QUEUE_FULL) {
498 SAS_DPRINTK("task: q busy, sleeping...\n");
499 schedule_timeout_interruptible(HZ);
500 } else if (task->task_status.stat == SAM_STAT_CHECK_CONDITION) {
501 struct scsi_sense_hdr shdr;
503 if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
505 SAS_DPRINTK("couldn't normalize sense\n");
508 if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
509 (shdr.sense_key == 2 && shdr.asc == 4 &&
511 SAS_DPRINTK("device %016llx LUN: %016llx "
512 "powering up or not ready yet, "
514 SAS_ADDR(task->dev->sas_addr),
515 SAS_ADDR(task->ssp_task.LUN));
517 schedule_timeout_interruptible(5*HZ);
518 } else if (shdr.sense_key == 1) {
521 } else if (shdr.sense_key == 5) {
524 SAS_DPRINTK("dev %016llx LUN: %016llx "
525 "sense key:0x%x ASC:0x%x ASCQ:0x%x"
527 SAS_ADDR(task->dev->sas_addr),
528 SAS_ADDR(task->ssp_task.LUN),
530 shdr.asc, shdr.ascq);
532 } else if (task->task_status.resp != SAS_TASK_COMPLETE ||
533 task->task_status.stat != SAM_STAT_GOOD) {
534 SAS_DPRINTK("task finished with resp:0x%x, "
536 task->task_status.resp,
537 task->task_status.stat);
545 if (dma_dir != DMA_NONE) {
546 if (sas_protocol_ata(task->task_proto))
547 dma_unmap_sg(task->dev->port->ha->dev,
548 task->scatter, task->num_scatter,
556 /* ---------- SATA ---------- */
558 static void sas_get_ata_command_set(struct domain_device *dev)
560 struct dev_to_host_fis *fis =
561 (struct dev_to_host_fis *) dev->frame_rcvd;
563 if ((fis->sector_count == 1 && /* ATA */
569 (fis->sector_count == 0 && /* CE-ATA (mATA) */
573 (fis->device & ~0x10) == 0))
575 dev->sata_dev.command_set = ATA_COMMAND_SET;
577 else if ((fis->interrupt_reason == 1 && /* ATAPI */
579 fis->byte_count_low == 0x14 &&
580 fis->byte_count_high == 0xEB &&
581 (fis->device & ~0x10) == 0))
583 dev->sata_dev.command_set = ATAPI_COMMAND_SET;
585 else if ((fis->sector_count == 1 && /* SEMB */
591 (fis->interrupt_reason == 1 && /* SATA PM */
593 fis->byte_count_low == 0x69 &&
594 fis->byte_count_high == 0x96 &&
595 (fis->device & ~0x10) == 0))
597 /* Treat it as a superset? */
598 dev->sata_dev.command_set = ATAPI_COMMAND_SET;
602 * sas_issue_ata_cmd -- Basic SATA command processing for discovery
603 * @dev: the device to send the command to
604 * @command: the command register
605 * @features: the features register
606 * @buffer: pointer to buffer to do I/O
607 * @size: size of @buffer
608 * @dma_dir: DMA direction. DMA_xxx
610 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
611 u8 features, void *buffer, int size,
612 enum dma_data_direction dma_dir)
615 struct sas_task *task;
616 struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
620 task = sas_alloc_task(GFP_KERNEL);
626 task->ata_task.fis.fis_type = 0x27;
627 task->ata_task.fis.command = command;
628 task->ata_task.fis.features = features;
629 task->ata_task.fis.device = d2h_fis->device;
630 task->ata_task.retry_count = 1;
632 res = sas_execute_task(task, buffer, size, dma_dir);
639 #define ATA_IDENTIFY_DEV 0xEC
640 #define ATA_IDENTIFY_PACKET_DEV 0xA1
641 #define ATA_SET_FEATURES 0xEF
642 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
645 * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
646 * @dev: STP/SATA device of interest (ATA/ATAPI)
648 * The LLDD has already been notified of this device, so that we can
649 * send FISes to it. Here we try to get IDENTIFY DEVICE or IDENTIFY
650 * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
651 * performance for this device.
653 static int sas_discover_sata_dev(struct domain_device *dev)
659 identify_x = kzalloc(512, GFP_KERNEL);
663 if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
664 dev->sata_dev.identify_device = identify_x;
665 command = ATA_IDENTIFY_DEV;
667 dev->sata_dev.identify_packet_device = identify_x;
668 command = ATA_IDENTIFY_PACKET_DEV;
671 res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
676 /* lives on the media? */
677 if (le16_to_cpu(identify_x[0]) & 4) {
678 /* incomplete response */
679 SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
680 "dev %llx\n", SAS_ADDR(dev->sas_addr));
681 if (!(identify_x[83] & cpu_to_le16(1<<6)))
683 res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
684 ATA_FEATURE_PUP_STBY_SPIN_UP,
689 schedule_timeout_interruptible(5*HZ); /* More time? */
690 res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
696 /* XXX Hint: register this SATA device with SATL.
697 When this returns, dev->sata_dev->lu is alive and
699 sas_satl_register_dev(dev);
702 sas_fill_in_rphy(dev, dev->rphy);
706 dev->sata_dev.identify_packet_device = NULL;
707 dev->sata_dev.identify_device = NULL;
712 static int sas_discover_sata_pm(struct domain_device *dev)
718 * sas_discover_sata -- discover an STP/SATA domain device
719 * @dev: pointer to struct domain_device of interest
721 * First we notify the LLDD of this device, so we can send frames to
722 * it. Then depending on the type of device we call the appropriate
723 * discover functions. Once device discover is done, we notify the
724 * LLDD so that it can fine-tune its parameters for the device, by
725 * removing it and then adding it. That is, the second time around,
726 * the driver would have certain fields, that it is looking at, set.
727 * Finally we initialize the kobj so that the device can be added to
728 * the system at registration time. Devices directly attached to a HA
729 * port, have no parents. All other devices do, and should have their
730 * "parent" pointer set appropriately before calling this function.
732 int sas_discover_sata(struct domain_device *dev)
736 sas_get_ata_command_set(dev);
738 res = sas_notify_lldd_dev_found(dev);
742 switch (dev->dev_type) {
744 res = sas_discover_sata_dev(dev);
747 res = sas_discover_sata_pm(dev);
752 sas_notify_lldd_dev_gone(dev);
754 sas_notify_lldd_dev_found(dev);
755 res = sas_rphy_add(dev->rphy);
761 void sas_ata_strategy_handler(struct Scsi_Host *shost)
763 struct scsi_device *sdev;
765 shost_for_each_device(sdev, shost) {
766 struct domain_device *ddev = sdev_to_domain_dev(sdev);
767 struct ata_port *ap = ddev->sata_dev.ap;
769 if (!dev_is_sata(ddev))
772 ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler");
773 ata_scsi_port_error_handler(shost, ap);
777 int sas_ata_timed_out(struct scsi_cmnd *cmd, struct sas_task *task,
778 enum blk_eh_timer_return *rtn)
780 struct domain_device *ddev = cmd_to_domain_dev(cmd);
782 if (!dev_is_sata(ddev) || task)
785 /* we're a sata device with no task, so this must be a libata
786 * eh timeout. Ideally should hook into libata timeout
787 * handling, but there's no point, it just wants to activate
789 *rtn = BLK_EH_NOT_HANDLED;
793 int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
794 struct list_head *done_q)
797 struct scsi_cmnd *cmd, *n;
805 list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
806 struct domain_device *ddev = cmd_to_domain_dev(cmd);
808 if (!dev_is_sata(ddev) || TO_SAS_TASK(cmd))
810 if (ap && ap != ddev->sata_dev.ap)
812 ap = ddev->sata_dev.ap;
814 list_move(&cmd->eh_entry, &sata_q);
817 if (!list_empty(&sata_q)) {
818 ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata cmd error handler\n");
819 ata_scsi_cmd_error_handler(shost, ap, &sata_q);
821 * ata's error handler may leave the cmd on the list
822 * so make sure they don't remain on a stack list
823 * about to go out of scope.
825 * This looks strange, since the commands are
826 * now part of no list, but the next error
827 * action will be ata_port_error_handler()
828 * which takes no list and sweeps them up
829 * anyway from the ata tag array.
831 while (!list_empty(&sata_q))
832 list_del_init(sata_q.next);