2 * libata-eh.c - libata error handling
4 * Maintained by: Jeff Garzik <jgarzik@pobox.com>
5 * Please ALWAYS copy linux-ide@vger.kernel.org
8 * Copyright 2006 Tejun Heo <htejun@gmail.com>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; see the file COPYING. If not, write to
23 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
27 * libata documentation is available via 'make {ps|pdf}docs',
28 * as Documentation/DocBook/libata.*
30 * Hardware documentation available from http://www.t13.org/ and
31 * http://www.sata-io.org/
35 #include <linux/config.h>
36 #include <linux/kernel.h>
37 #include <scsi/scsi.h>
38 #include <scsi/scsi_host.h>
39 #include <scsi/scsi_eh.h>
40 #include <scsi/scsi_device.h>
41 #include <scsi/scsi_cmnd.h>
43 #include <linux/libata.h>
48 * ata_scsi_timed_out - SCSI layer time out callback
49 * @cmd: timed out SCSI command
51 * Handles SCSI layer timeout. We race with normal completion of
52 * the qc for @cmd. If the qc is already gone, we lose and let
53 * the scsi command finish (EH_HANDLED). Otherwise, the qc has
54 * timed out and EH should be invoked. Prevent ata_qc_complete()
55 * from finishing it by setting EH_SCHEDULED and return
59 * Called from timer context
62 * EH_HANDLED or EH_NOT_HANDLED
64 enum scsi_eh_timer_return
ata_scsi_timed_out(struct scsi_cmnd
*cmd
)
66 struct Scsi_Host
*host
= cmd
->device
->host
;
67 struct ata_port
*ap
= ata_shost_to_port(host
);
69 struct ata_queued_cmd
*qc
;
70 enum scsi_eh_timer_return ret
= EH_HANDLED
;
74 spin_lock_irqsave(&ap
->host_set
->lock
, flags
);
75 qc
= ata_qc_from_tag(ap
, ap
->active_tag
);
77 WARN_ON(qc
->scsicmd
!= cmd
);
78 qc
->flags
|= ATA_QCFLAG_EH_SCHEDULED
;
79 qc
->err_mask
|= AC_ERR_TIMEOUT
;
82 spin_unlock_irqrestore(&ap
->host_set
->lock
, flags
);
84 DPRINTK("EXIT, ret=%d\n", ret
);
89 * ata_scsi_error - SCSI layer error handler callback
90 * @host: SCSI host on which error occurred
92 * Handles SCSI-layer-thrown error events.
95 * Inherited from SCSI layer (none, can sleep)
100 void ata_scsi_error(struct Scsi_Host
*host
)
102 struct ata_port
*ap
= ata_shost_to_port(host
);
106 /* synchronize with IRQ handler and port task */
107 spin_unlock_wait(&ap
->host_set
->lock
);
108 ata_port_flush_task(ap
);
110 WARN_ON(ata_qc_from_tag(ap
, ap
->active_tag
) == NULL
);
112 ap
->ops
->eng_timeout(ap
);
114 WARN_ON(host
->host_failed
|| !list_empty(&host
->eh_cmd_q
));
116 scsi_eh_flush_done_q(&ap
->eh_done_q
);
122 * ata_qc_timeout - Handle timeout of queued command
123 * @qc: Command that timed out
125 * Some part of the kernel (currently, only the SCSI layer)
126 * has noticed that the active command on port @ap has not
127 * completed after a specified length of time. Handle this
128 * condition by disabling DMA (if necessary) and completing
129 * transactions, with error if necessary.
131 * This also handles the case of the "lost interrupt", where
132 * for some reason (possibly hardware bug, possibly driver bug)
133 * an interrupt was not delivered to the driver, even though the
134 * transaction completed successfully.
137 * Inherited from SCSI layer (none, can sleep)
139 static void ata_qc_timeout(struct ata_queued_cmd
*qc
)
141 struct ata_port
*ap
= qc
->ap
;
142 struct ata_host_set
*host_set
= ap
->host_set
;
143 u8 host_stat
= 0, drv_stat
;
148 ap
->hsm_task_state
= HSM_ST_IDLE
;
150 spin_lock_irqsave(&host_set
->lock
, flags
);
152 switch (qc
->tf
.protocol
) {
155 case ATA_PROT_ATAPI_DMA
:
156 host_stat
= ap
->ops
->bmdma_status(ap
);
158 /* before we do anything else, clear DMA-Start bit */
159 ap
->ops
->bmdma_stop(qc
);
165 drv_stat
= ata_chk_status(ap
);
167 /* ack bmdma irq events */
168 ap
->ops
->irq_clear(ap
);
170 ata_dev_printk(qc
->dev
, KERN_ERR
, "command 0x%x timeout, "
171 "stat 0x%x host_stat 0x%x\n",
172 qc
->tf
.command
, drv_stat
, host_stat
);
174 /* complete taskfile transaction */
175 qc
->err_mask
|= ac_err_mask(drv_stat
);
179 spin_unlock_irqrestore(&host_set
->lock
, flags
);
181 ata_eh_qc_complete(qc
);
187 * ata_eng_timeout - Handle timeout of queued command
188 * @ap: Port on which timed-out command is active
190 * Some part of the kernel (currently, only the SCSI layer)
191 * has noticed that the active command on port @ap has not
192 * completed after a specified length of time. Handle this
193 * condition by disabling DMA (if necessary) and completing
194 * transactions, with error if necessary.
196 * This also handles the case of the "lost interrupt", where
197 * for some reason (possibly hardware bug, possibly driver bug)
198 * an interrupt was not delivered to the driver, even though the
199 * transaction completed successfully.
202 * Inherited from SCSI layer (none, can sleep)
204 void ata_eng_timeout(struct ata_port
*ap
)
208 ata_qc_timeout(ata_qc_from_tag(ap
, ap
->active_tag
));
213 static void ata_eh_scsidone(struct scsi_cmnd
*scmd
)
218 static void __ata_eh_qc_complete(struct ata_queued_cmd
*qc
)
220 struct ata_port
*ap
= qc
->ap
;
221 struct scsi_cmnd
*scmd
= qc
->scsicmd
;
224 spin_lock_irqsave(&ap
->host_set
->lock
, flags
);
225 qc
->scsidone
= ata_eh_scsidone
;
226 __ata_qc_complete(qc
);
227 WARN_ON(ata_tag_valid(qc
->tag
));
228 spin_unlock_irqrestore(&ap
->host_set
->lock
, flags
);
230 scsi_eh_finish_cmd(scmd
, &ap
->eh_done_q
);
234 * ata_eh_qc_complete - Complete an active ATA command from EH
235 * @qc: Command to complete
237 * Indicate to the mid and upper layers that an ATA command has
238 * completed. To be used from EH.
240 void ata_eh_qc_complete(struct ata_queued_cmd
*qc
)
242 struct scsi_cmnd
*scmd
= qc
->scsicmd
;
243 scmd
->retries
= scmd
->allowed
;
244 __ata_eh_qc_complete(qc
);
248 * ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
249 * @qc: Command to retry
251 * Indicate to the mid and upper layers that an ATA command
252 * should be retried. To be used from EH.
254 * SCSI midlayer limits the number of retries to scmd->allowed.
255 * scmd->retries is decremented for commands which get retried
256 * due to unrelated failures (qc->err_mask is zero).
258 void ata_eh_qc_retry(struct ata_queued_cmd
*qc
)
260 struct scsi_cmnd
*scmd
= qc
->scsicmd
;
261 if (!qc
->err_mask
&& scmd
->retries
)
263 __ata_eh_qc_complete(qc
);
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