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[PATCH] libata: implement standard reset component operations and ->p…
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…robe_reset

Implement SRST, COMRESET and standard postreset component operations
for ata_drive_probe_reset(), and use these three functions to
implement ata_std_probe_reset.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
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Tejun Heo authored and Jeff Garzik committed Jan 28, 2006
1 parent a62c0fc commit c2bd580
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206 changes: 206 additions & 0 deletions drivers/scsi/libata-core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2233,6 +2233,208 @@ void ata_bus_reset(struct ata_port *ap)
DPRINTK("EXIT\n");
}

/**
* ata_std_softreset - reset host port via ATA SRST
* @ap: port to reset
* @verbose: fail verbosely
* @classes: resulting classes of attached devices
*
* Reset host port using ATA SRST. This function is to be used
* as standard callback for ata_drive_*_reset() functions.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno otherwise.
*/
int ata_std_softreset(struct ata_port *ap, int verbose, unsigned int *classes)
{
unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
unsigned int devmask = 0, err_mask;
u8 err;

DPRINTK("ENTER\n");

/* determine if device 0/1 are present */
if (ata_devchk(ap, 0))
devmask |= (1 << 0);
if (slave_possible && ata_devchk(ap, 1))
devmask |= (1 << 1);

/* devchk reports device presence without actual device on
* most SATA controllers. Check SStatus and turn devmask off
* if link is offline. Note that we should continue resetting
* even when it seems like there's no device.
*/
if (ap->ops->scr_read && !sata_dev_present(ap))
devmask = 0;

/* select device 0 again */
ap->ops->dev_select(ap, 0);

/* issue bus reset */
DPRINTK("about to softreset, devmask=%x\n", devmask);
err_mask = ata_bus_softreset(ap, devmask);
if (err_mask) {
if (verbose)
printk(KERN_ERR "ata%u: SRST failed (err_mask=0x%x)\n",
ap->id, err_mask);
else
DPRINTK("EXIT, softreset failed (err_mask=0x%x)\n",
err_mask);
return -EIO;
}

/* determine by signature whether we have ATA or ATAPI devices */
classes[0] = ata_dev_try_classify(ap, 0, &err);
if (slave_possible && err != 0x81)
classes[1] = ata_dev_try_classify(ap, 1, &err);

DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
return 0;
}

/**
* sata_std_hardreset - reset host port via SATA phy reset
* @ap: port to reset
* @verbose: fail verbosely
* @class: resulting class of attached device
*
* SATA phy-reset host port using DET bits of SControl register.
* This function is to be used as standard callback for
* ata_drive_*_reset().
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno otherwise.
*/
int sata_std_hardreset(struct ata_port *ap, int verbose, unsigned int *class)
{
u32 sstatus, serror;
unsigned long timeout = jiffies + (HZ * 5);

DPRINTK("ENTER\n");

/* Issue phy wake/reset */
scr_write_flush(ap, SCR_CONTROL, 0x301);

/*
* Couldn't find anything in SATA I/II specs, but AHCI-1.1
* 10.4.2 says at least 1 ms.
*/
msleep(1);

scr_write_flush(ap, SCR_CONTROL, 0x300);

/* Wait for phy to become ready, if necessary. */
do {
msleep(200);
sstatus = scr_read(ap, SCR_STATUS);
if ((sstatus & 0xf) != 1)
break;
} while (time_before(jiffies, timeout));

/* Clear SError */
serror = scr_read(ap, SCR_ERROR);
scr_write(ap, SCR_ERROR, serror);

/* TODO: phy layer with polling, timeouts, etc. */
if (!sata_dev_present(ap)) {
*class = ATA_DEV_NONE;
DPRINTK("EXIT, link offline\n");
return 0;
}

if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
if (verbose)
printk(KERN_ERR "ata%u: COMRESET failed "
"(device not ready)\n", ap->id);
else
DPRINTK("EXIT, device not ready\n");
return -EIO;
}

*class = ata_dev_try_classify(ap, 0, NULL);

DPRINTK("EXIT, class=%u\n", *class);
return 0;
}

/**
* ata_std_postreset - standard postreset callback
* @ap: the target ata_port
* @classes: classes of attached devices
*
* This function is invoked after a successful reset. Note that
* the device might have been reset more than once using
* different reset methods before postreset is invoked.
* postreset is also reponsible for setting cable type.
*
* This function is to be used as standard callback for
* ata_drive_*_reset().
*
* LOCKING:
* Kernel thread context (may sleep)
*/
void ata_std_postreset(struct ata_port *ap, unsigned int *classes)
{
DPRINTK("ENTER\n");

/* set cable type */
if (ap->cbl == ATA_CBL_NONE && ap->flags & ATA_FLAG_SATA)
ap->cbl = ATA_CBL_SATA;

/* print link status */
if (ap->cbl == ATA_CBL_SATA)
sata_print_link_status(ap);

/* bail out if no device is present */
if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
DPRINTK("EXIT, no device\n");
return;
}

/* is double-select really necessary? */
if (classes[0] != ATA_DEV_NONE)
ap->ops->dev_select(ap, 1);
if (classes[1] != ATA_DEV_NONE)
ap->ops->dev_select(ap, 0);

/* re-enable interrupts & set up device control */
if (ap->ioaddr.ctl_addr) /* FIXME: hack. create a hook instead */
ata_irq_on(ap);

DPRINTK("EXIT\n");
}

/**
* ata_std_probe_reset - standard probe reset method
* @ap: prot to perform probe-reset
* @classes: resulting classes of attached devices
*
* The stock off-the-shelf ->probe_reset method.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno otherwise.
*/
int ata_std_probe_reset(struct ata_port *ap, unsigned int *classes)
{
ata_reset_fn_t hardreset;

hardreset = NULL;
if (ap->cbl == ATA_CBL_SATA && ap->ops->scr_read)
hardreset = sata_std_hardreset;

return ata_drive_probe_reset(ap, ata_std_softreset, hardreset,
ata_std_postreset, classes);
}

static int do_probe_reset(struct ata_port *ap, ata_reset_fn_t reset,
ata_postreset_fn_t postreset,
unsigned int *classes)
Expand Down Expand Up @@ -5268,6 +5470,10 @@ EXPORT_SYMBOL_GPL(ata_port_probe);
EXPORT_SYMBOL_GPL(sata_phy_reset);
EXPORT_SYMBOL_GPL(__sata_phy_reset);
EXPORT_SYMBOL_GPL(ata_bus_reset);
EXPORT_SYMBOL_GPL(ata_std_softreset);
EXPORT_SYMBOL_GPL(sata_std_hardreset);
EXPORT_SYMBOL_GPL(ata_std_postreset);
EXPORT_SYMBOL_GPL(ata_std_probe_reset);
EXPORT_SYMBOL_GPL(ata_drive_probe_reset);
EXPORT_SYMBOL_GPL(ata_port_disable);
EXPORT_SYMBOL_GPL(ata_ratelimit);
Expand Down
6 changes: 6 additions & 0 deletions include/linux/libata.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -483,6 +483,11 @@ extern void ata_bus_reset(struct ata_port *ap);
extern int ata_drive_probe_reset(struct ata_port *ap,
ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
ata_postreset_fn_t postreset, unsigned int *classes);
extern int ata_std_softreset(struct ata_port *ap, int verbose,
unsigned int *classes);
extern int sata_std_hardreset(struct ata_port *ap, int verbose,
unsigned int *class);
extern void ata_std_postreset(struct ata_port *ap, unsigned int *classes);
extern void ata_port_disable(struct ata_port *);
extern void ata_std_ports(struct ata_ioports *ioaddr);
#ifdef CONFIG_PCI
Expand Down Expand Up @@ -523,6 +528,7 @@ extern void ata_std_dev_select (struct ata_port *ap, unsigned int device);
extern u8 ata_check_status(struct ata_port *ap);
extern u8 ata_altstatus(struct ata_port *ap);
extern void ata_exec_command(struct ata_port *ap, const struct ata_taskfile *tf);
extern int ata_std_probe_reset(struct ata_port *ap, unsigned int *classes);
extern int ata_port_start (struct ata_port *ap);
extern void ata_port_stop (struct ata_port *ap);
extern void ata_host_stop (struct ata_host_set *host_set);
Expand Down

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