FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2024-12-20 00:11:22 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[PATCH] libata-eh-fw: use special reserved tag and qc for internal commands

Browse Source 
New EH may issue internal commands to recover from error while failed
qc's are still hanging around.  To allow such usage, reserve tag
ATA_MAX_QUEUE-1 for internal command.  This also makes it easy to tell
whether a qc is for internal command or not.  ata_tag_internal() test
implements this test.

To avoid breaking existing drivers, ata_exec_internal() uses
ATA_TAG_INTERNAL only for drivers which implement ->error_handler.
For drivers using old EH, tag 0 is used.  Note that this makes
ata_tag_internal() test valid only when ->error_handler is
implemented.  This is okay as drivers on old EH should not and does
not have any reason to use ata_tag_internal().

Signed-off-by: Tejun Heo <htejun@gmail.com>
This commit is contained in:
Tejun Heo 2006-05-15 20:58:02 +09:00
parent dc2b351586
commit 2ab7db1ff1
2 changed files with 37 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/scsi/libata-core.c
View File

@ -980,15 +980,39 @@ unsigned ata_exec_internal(struct ata_device *dev,
struct ata_port *ap = dev->ap;
u8 command = tf->command;
struct ata_queued_cmd *qc;
unsigned int tag, preempted_tag;
DECLARE_COMPLETION(wait);
unsigned long flags;
unsigned int err_mask;
spin_lock_irqsave(&ap->host_set->lock, flags);
qc = ata_qc_new_init(dev);
BUG_ON(qc == NULL);
/* initialize internal qc */
/* XXX: Tag 0 is used for drivers with legacy EH as some
* drivers choke if any other tag is given. This breaks
* ata_tag_internal() test for those drivers. Don't use new
* EH stuff without converting to it.
*/
if (ap->ops->error_handler)
tag = ATA_TAG_INTERNAL;
else
tag = 0;
if (test_and_set_bit(tag, &ap->qactive))
BUG();
qc = ata_qc_from_tag(ap, tag);
qc->tag = tag;
qc->scsicmd = NULL;
qc->ap = ap;
qc->dev = dev;
ata_qc_reinit(qc);
preempted_tag = ap->active_tag;
ap->active_tag = ATA_TAG_POISON;
/* prepare & issue qc */
qc->tf = *tf;
if (cdb)
memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
@ -1035,6 +1059,7 @@ unsigned ata_exec_internal(struct ata_device *dev,
err_mask = qc->err_mask;
ata_qc_free(qc);
ap->active_tag = preempted_tag;
/* XXX - Some LLDDs (sata_mv) disable port on command failure.
* Until those drivers are fixed, we detect the condition
@ -4014,7 +4039,8 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
struct ata_queued_cmd *qc = NULL;
unsigned int i;
for (i = 0; i < ATA_MAX_QUEUE; i++)
/* the last tag is reserved for internal command. */
for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
if (!test_and_set_bit(i, &ap->qactive)) {
qc = ata_qc_from_tag(ap, i);
break;

9
include/linux/libata.h
View File

@ -108,7 +108,9 @@ enum {
LIBATA_MAX_PRD = ATA_MAX_PRD / 2,
ATA_MAX_PORTS = 8,
ATA_DEF_QUEUE = 1,
ATA_MAX_QUEUE = 1,
/* tag ATA_MAX_QUEUE - 1 is reserved for internal commands */
ATA_MAX_QUEUE = 2,
ATA_TAG_INTERNAL = ATA_MAX_QUEUE - 1,
ATA_MAX_SECTORS = 200, /* FIXME */
ATA_MAX_BUS = 2,
ATA_DEF_BUSY_WAIT = 10000,
@ -717,6 +719,11 @@ static inline unsigned int ata_tag_valid(unsigned int tag)
return (tag < ATA_MAX_QUEUE) ? 1 : 0;
}
static inline unsigned int ata_tag_internal(unsigned int tag)
{
return tag == ATA_MAX_QUEUE - 1;
}
static inline unsigned int ata_class_enabled(unsigned int class)
{
return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI;