in libata-eh.c [2438:2842]
int ata_eh_reset(struct ata_link *link, int classify,
ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
{
struct ata_port *ap = link->ap;
struct ata_link *slave = ap->slave_link;
struct ata_eh_context *ehc = &link->eh_context;
struct ata_eh_context *sehc = slave ? &slave->eh_context : NULL;
unsigned int *classes = ehc->classes;
unsigned int lflags = link->flags;
int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
int max_tries = 0, try = 0;
struct ata_link *failed_link;
struct ata_device *dev;
unsigned long deadline, now;
ata_reset_fn_t reset;
unsigned long flags;
u32 sstatus;
int nr_unknown, rc;
/*
* Prepare to reset
*/
while (ata_eh_reset_timeouts[max_tries] != ULONG_MAX)
max_tries++;
if (link->flags & ATA_LFLAG_RST_ONCE)
max_tries = 1;
if (link->flags & ATA_LFLAG_NO_HRST)
hardreset = NULL;
if (link->flags & ATA_LFLAG_NO_SRST)
softreset = NULL;
/* make sure each reset attempt is at least COOL_DOWN apart */
if (ehc->i.flags & ATA_EHI_DID_RESET) {
now = jiffies;
WARN_ON(time_after(ehc->last_reset, now));
deadline = ata_deadline(ehc->last_reset,
ATA_EH_RESET_COOL_DOWN);
if (time_before(now, deadline))
schedule_timeout_uninterruptible(deadline - now);
}
spin_lock_irqsave(ap->lock, flags);
ap->pflags |= ATA_PFLAG_RESETTING;
spin_unlock_irqrestore(ap->lock, flags);
ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
ata_for_each_dev(dev, link, ALL) {
/* If we issue an SRST then an ATA drive (not ATAPI)
* may change configuration and be in PIO0 timing. If
* we do a hard reset (or are coming from power on)
* this is true for ATA or ATAPI. Until we've set a
* suitable controller mode we should not touch the
* bus as we may be talking too fast.
*/
dev->pio_mode = XFER_PIO_0;
dev->dma_mode = 0xff;
/* If the controller has a pio mode setup function
* then use it to set the chipset to rights. Don't
* touch the DMA setup as that will be dealt with when
* configuring devices.
*/
if (ap->ops->set_piomode)
ap->ops->set_piomode(ap, dev);
}
/* prefer hardreset */
reset = NULL;
ehc->i.action &= ~ATA_EH_RESET;
if (hardreset) {
reset = hardreset;
ehc->i.action |= ATA_EH_HARDRESET;
} else if (softreset) {
reset = softreset;
ehc->i.action |= ATA_EH_SOFTRESET;
}
if (prereset) {
unsigned long deadline = ata_deadline(jiffies,
ATA_EH_PRERESET_TIMEOUT);
if (slave) {
sehc->i.action &= ~ATA_EH_RESET;
sehc->i.action |= ehc->i.action;
}
rc = prereset(link, deadline);
/* If present, do prereset on slave link too. Reset
* is skipped iff both master and slave links report
* -ENOENT or clear ATA_EH_RESET.
*/
if (slave && (rc == 0 || rc == -ENOENT)) {
int tmp;
tmp = prereset(slave, deadline);
if (tmp != -ENOENT)
rc = tmp;
ehc->i.action |= sehc->i.action;
}
if (rc) {
if (rc == -ENOENT) {
ata_link_dbg(link, "port disabled--ignoring\n");
ehc->i.action &= ~ATA_EH_RESET;
ata_for_each_dev(dev, link, ALL)
classes[dev->devno] = ATA_DEV_NONE;
rc = 0;
} else
ata_link_err(link,
"prereset failed (errno=%d)\n",
rc);
goto out;
}
/* prereset() might have cleared ATA_EH_RESET. If so,
* bang classes, thaw and return.
*/
if (reset && !(ehc->i.action & ATA_EH_RESET)) {
ata_for_each_dev(dev, link, ALL)
classes[dev->devno] = ATA_DEV_NONE;
if ((ap->pflags & ATA_PFLAG_FROZEN) &&
ata_is_host_link(link))
ata_eh_thaw_port(ap);
rc = 0;
goto out;
}
}
retry:
/*
* Perform reset
*/
if (ata_is_host_link(link))
ata_eh_freeze_port(ap);
deadline = ata_deadline(jiffies, ata_eh_reset_timeouts[try++]);
if (reset) {
if (verbose)
ata_link_info(link, "%s resetting link\n",
reset == softreset ? "soft" : "hard");
/* mark that this EH session started with reset */
ehc->last_reset = jiffies;
if (reset == hardreset) {
ehc->i.flags |= ATA_EHI_DID_HARDRESET;
trace_ata_link_hardreset_begin(link, classes, deadline);
} else {
ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
trace_ata_link_softreset_begin(link, classes, deadline);
}
rc = ata_do_reset(link, reset, classes, deadline, true);
if (reset == hardreset)
trace_ata_link_hardreset_end(link, classes, rc);
else
trace_ata_link_softreset_end(link, classes, rc);
if (rc && rc != -EAGAIN) {
failed_link = link;
goto fail;
}
/* hardreset slave link if existent */
if (slave && reset == hardreset) {
int tmp;
if (verbose)
ata_link_info(slave, "hard resetting link\n");
ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
trace_ata_slave_hardreset_begin(slave, classes,
deadline);
tmp = ata_do_reset(slave, reset, classes, deadline,
false);
trace_ata_slave_hardreset_end(slave, classes, tmp);
switch (tmp) {
case -EAGAIN:
rc = -EAGAIN;
break;
case 0:
break;
default:
failed_link = slave;
rc = tmp;
goto fail;
}
}
/* perform follow-up SRST if necessary */
if (reset == hardreset &&
ata_eh_followup_srst_needed(link, rc)) {
reset = softreset;
if (!reset) {
ata_link_err(link,
"follow-up softreset required but no softreset available\n");
failed_link = link;
rc = -EINVAL;
goto fail;
}
ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
trace_ata_link_softreset_begin(link, classes, deadline);
rc = ata_do_reset(link, reset, classes, deadline, true);
trace_ata_link_softreset_end(link, classes, rc);
if (rc) {
failed_link = link;
goto fail;
}
}
} else {
if (verbose)
ata_link_info(link,
"no reset method available, skipping reset\n");
if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
lflags |= ATA_LFLAG_ASSUME_ATA;
}
/*
* Post-reset processing
*/
ata_for_each_dev(dev, link, ALL) {
/* After the reset, the device state is PIO 0 and the
* controller state is undefined. Reset also wakes up
* drives from sleeping mode.
*/
dev->pio_mode = XFER_PIO_0;
dev->flags &= ~ATA_DFLAG_SLEEPING;
if (ata_phys_link_offline(ata_dev_phys_link(dev)))
continue;
/* apply class override */
if (lflags & ATA_LFLAG_ASSUME_ATA)
classes[dev->devno] = ATA_DEV_ATA;
else if (lflags & ATA_LFLAG_ASSUME_SEMB)
classes[dev->devno] = ATA_DEV_SEMB_UNSUP;
}
/* record current link speed */
if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
link->sata_spd = (sstatus >> 4) & 0xf;
if (slave && sata_scr_read(slave, SCR_STATUS, &sstatus) == 0)
slave->sata_spd = (sstatus >> 4) & 0xf;
/* thaw the port */
if (ata_is_host_link(link))
ata_eh_thaw_port(ap);
/* postreset() should clear hardware SError. Although SError
* is cleared during link resume, clearing SError here is
* necessary as some PHYs raise hotplug events after SRST.
* This introduces race condition where hotplug occurs between
* reset and here. This race is mediated by cross checking
* link onlineness and classification result later.
*/
if (postreset) {
postreset(link, classes);
trace_ata_link_postreset(link, classes, rc);
if (slave) {
postreset(slave, classes);
trace_ata_slave_postreset(slave, classes, rc);
}
}
/*
* Some controllers can't be frozen very well and may set spurious
* error conditions during reset. Clear accumulated error
* information and re-thaw the port if frozen. As reset is the
* final recovery action and we cross check link onlineness against
* device classification later, no hotplug event is lost by this.
*/
spin_lock_irqsave(link->ap->lock, flags);
memset(&link->eh_info, 0, sizeof(link->eh_info));
if (slave)
memset(&slave->eh_info, 0, sizeof(link->eh_info));
ap->pflags &= ~ATA_PFLAG_EH_PENDING;
spin_unlock_irqrestore(link->ap->lock, flags);
if (ap->pflags & ATA_PFLAG_FROZEN)
ata_eh_thaw_port(ap);
/*
* Make sure onlineness and classification result correspond.
* Hotplug could have happened during reset and some
* controllers fail to wait while a drive is spinning up after
* being hotplugged causing misdetection. By cross checking
* link on/offlineness and classification result, those
* conditions can be reliably detected and retried.
*/
nr_unknown = 0;
ata_for_each_dev(dev, link, ALL) {
if (ata_phys_link_online(ata_dev_phys_link(dev))) {
if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
ata_dev_dbg(dev, "link online but device misclassified\n");
classes[dev->devno] = ATA_DEV_NONE;
nr_unknown++;
}
} else if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
if (ata_class_enabled(classes[dev->devno]))
ata_dev_dbg(dev,
"link offline, clearing class %d to NONE\n",
classes[dev->devno]);
classes[dev->devno] = ATA_DEV_NONE;
} else if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
ata_dev_dbg(dev,
"link status unknown, clearing UNKNOWN to NONE\n");
classes[dev->devno] = ATA_DEV_NONE;
}
}
if (classify && nr_unknown) {
if (try < max_tries) {
ata_link_warn(link,
"link online but %d devices misclassified, retrying\n",
nr_unknown);
failed_link = link;
rc = -EAGAIN;
goto fail;
}
ata_link_warn(link,
"link online but %d devices misclassified, "
"device detection might fail\n", nr_unknown);
}
/* reset successful, schedule revalidation */
ata_eh_done(link, NULL, ATA_EH_RESET);
if (slave)
ata_eh_done(slave, NULL, ATA_EH_RESET);
ehc->last_reset = jiffies; /* update to completion time */
ehc->i.action |= ATA_EH_REVALIDATE;
link->lpm_policy = ATA_LPM_UNKNOWN; /* reset LPM state */
rc = 0;
out:
/* clear hotplug flag */
ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
if (slave)
sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
spin_lock_irqsave(ap->lock, flags);
ap->pflags &= ~ATA_PFLAG_RESETTING;
spin_unlock_irqrestore(ap->lock, flags);
return rc;
fail:
/* if SCR isn't accessible on a fan-out port, PMP needs to be reset */
if (!ata_is_host_link(link) &&
sata_scr_read(link, SCR_STATUS, &sstatus))
rc = -ERESTART;
if (try >= max_tries) {
/*
* Thaw host port even if reset failed, so that the port
* can be retried on the next phy event. This risks
* repeated EH runs but seems to be a better tradeoff than
* shutting down a port after a botched hotplug attempt.
*/
if (ata_is_host_link(link))
ata_eh_thaw_port(ap);
goto out;
}
now = jiffies;
if (time_before(now, deadline)) {
unsigned long delta = deadline - now;
ata_link_warn(failed_link,
"reset failed (errno=%d), retrying in %u secs\n",
rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));
ata_eh_release(ap);
while (delta)
delta = schedule_timeout_uninterruptible(delta);
ata_eh_acquire(ap);
}
/*
* While disks spinup behind PMP, some controllers fail sending SRST.
* They need to be reset - as well as the PMP - before retrying.
*/
if (rc == -ERESTART) {
if (ata_is_host_link(link))
ata_eh_thaw_port(ap);
goto out;
}
if (try == max_tries - 1) {
sata_down_spd_limit(link, 0);
if (slave)
sata_down_spd_limit(slave, 0);
} else if (rc == -EPIPE)
sata_down_spd_limit(failed_link, 0);
if (hardreset)
reset = hardreset;
goto retry;
}