libata EH used to ignore errors not associated with commands when
determining whether speed down is necessary or not.  This leads to the
following problems.

* Errors not associated with commands can occur indefinitely without
  libata EH taking corrective actions.

* Upstream link errors don't trigger speed down when PMP is attached
  to it and commands issued to downstream device trigger errors on the
  upstream link.

This patch makes ata_eh_link_autopsy() consider errors not associated
with command for speed down.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Reset failure is a critical error.  It results in disabling the link
requiring user intervention to re-enable it.  Make reset failure
handling more robust such that libata EH doesn't give up too early.

* Temporary glitches during hardreset may lead to classification
  failure when there's no softreset available.  Retry instead of
  giving up.

* Initial softreset or follow up softreset may fail classification.
  Move classification error handling block out of followup softreset
  block such that both cases are handled and retry instead of giving
  up.  Also, on the last try, give ATA class a blind shot.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Clean up and reorganize ata_eh_reset() to ease further changes.

* Cache ARRAY_SIZE(ata_eh_reset_timeouts) in @max_tries.
* Cache link->flags in @lflags.
* Move failure handling block to the end of the function and unnest
  both success and failure handling blocks.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

As jiffies changes asynchronously, it needs to be cached if unchanging
timestamp is needed.  The code in ata_eh_reset() intended to do that
with @now but never actually did it.  Fix it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_QCFLAG_QUIET which indicates that there's no need to
report if the command fails with AC_ERR_DEV and set it for passthrough
commands.

Combined with previous changes, this now makes device errors for all
direct commands reported directly to the issuer without going through
EH actions and reporting.

Note that EH is still invoked after non-IO device errors to determine
the nature of the error and resume command execution (some controller
requires special care after error to continue).  It just performs
default maintenance after error, examines what's going on, realizes
that it's none of its business and reports the command failure without
logging any error messages.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata EH always revalidated device and retried failed command after
error except for ATAPI CCs.  This is unnecessary and hinders with
users issuing direct commands.  This patch makes the following
changes.

* Make sata_sil24 not request ATA_EH_REVALIDATE on device errors.
  sil24 is the only driver which does this.  All others let libata EH
  core code decide.

* Don't request revalidation after device error of non-IO command.
  Revalidation doesn't really help anybody.  As ATA_EH_REVALIDATE
  isn't set by default, there's no reason to clear it after sense data
  is read.  Kill ATA_EH_REVALIDATE clearing code while at it.

* Don't retry non-IO command after device error.  Device has rejected
  the command.  There's no point in retrying.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Device Initiated Power Management, which is defined
in SATA 2.5 can be enabled for disks which support it.
This patch enables DIPM when the user sets the link
power management policy to "min_power".

Additionally, libata drivers can define a function
(enable_pm) that will perform hardware specific actions to
enable whatever power management policy the user set up
for Host Initiated Power management (HIPM).
This power management policy will be activated after all
disks have been enumerated and intialized.  Drivers should
also define disable_pm, which will turn off link power
management, but not change link power management policy.

Documentation/scsi/link_power_management_policy.txt has additional
information.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

After reset, transfer mode is always PIO0 regardless of
dev->xfer_mask.  Check dev->pio_mode before trying to slow down after
configuration failure.  This prevents bogus speed down before device
is actually configured.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Forcing PIO0 on reset was done inside ata_bus_softreset(), which is a
bit out of place as it should be applied to all resets - hard, soft
and implementation which don't use ata_bus_softreset().  Relocate it
such that...

* For new EH, it's done in ata_eh_reset() before calling prereset.

* For old EH, it's done before calling ap->ops->phy_reset() in
  ata_bus_probe().

This makes PIO0 forced after all resets.  Another difference is that
reset itself is done after PIO0 is forced.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ATA devices in SLEEP mode don't respond to any commands.  SRST is
necessary to wake it up.  Till now, when a command is issued to a
device in SLEEP mode, the command times out, which makes EH reset the
device and retry the command after that, causing a long delay.

This patch makes libata track SLEEP state and issue SRST automatically
if a command is about to be issued to a device in SLEEP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Bruce Allen <ballen@gravity.phys.uwm.edu>
Cc: Andrew Paprocki <andrew@ishiboo.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Local variable @action usage in ata_eh_reset() is a bit confusing.
It's used only to cache ehc->i.action to test reset masks after
clearing it; however, due to the generic name "action", it's easy to
misinterpret the local variable as containing the selected reset
method later.  Also, the reason for caching the original value is easy
to miss.

This patch renames @action to @tmp_action and make it buffer newly
selected value instead to improve readability.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Tackle the relatively sane complaints of checkpatch --file.

The vast majority is indentation and whitespace changes, the rest are

* #include fixes
* printk KERN_xxx prefix addition
* BSS/initializer cleanups
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

* remove pointless pci_dev_to_dev() wrapper.  Just directly reference
  the embedded struct device like everyone else does.

* pata_cs5520: delete cs5520_remove_one(), it was a duplicate of
  ata_pci_remove_one()

* linux/libata.h: don't bother including linux/pci.h, we don't need it.
  Simply declare 'struct pci_dev' and assume interested parties will
  include the header, as they should be doing anyway.

* linux/libata.h: consolidate all CONFIG_PCI declarations into a
  single location in the header.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

PMP registers used to be accessed with dedicated accessors ->pmp_read
and ->pmp_write.  During reset, those callbacks are called with the
port frozen so they should be able to run without depending on
interrupt delivery.  To achieve this, they were implemented polling.

However, as resetting the host port makes the PMP to isolate fan-out
ports until SError.X is cleared, resetting fan-out ports while port is
frozen doesn't buy much additional safety.

This patch updates libata PMP support such that PMP registers are
accessed using regular ata_exec_internal() mechanism and kills
->pmp_read/write() callbacks.  The following changes are made.

* PMP access helpers - sata_pmp_read_init_tf(), sata_pmp_read_val(),
  sata_pmp_write_init_tf() are folded into sata_pmp_read/write() which
  are now standalone PMP register access functions.

* sata_pmp_read/write() returns err_mask instead of rc.  This is
  consistent with other functions which issue internal commands and
  allows more detailed error reporting.

* ahci interrupt handler is modified to ignore BAD_PMP and
  spurious/illegal completion IRQs while reset is in progress.  These
  conditions are expected during reset.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_PFLAG_RESETTING.  This flag is set while reset is in
progress.  It's set before prereset is called and cleared after reset
fails or postreset is finished.

This flag itself doesn't have any function.  It will be used by LLDs
to tell whether reset is in progress if it needs to behave differently
during reset.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add @timeout argument to ata_exec_internal[_sg]().  If 0, default
timeout ata_probe_timeout is used.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Tasks in uninterruptible sleep might be woken up by unrelated events
and should check whether the condition it was waiting for has actually
triggered.  Wrap schedule_timeout_uninterruptible() in loop to achieve
it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ATA_EHI_NO_AUTOPSY and ATA_EHI_QUIET are used during initial probing
to skip exception analysis and reporting.  Usually, there's nothing to
report but on some allowed but rare corner cases (e.g. phy status
changed interrupt when IRQ is enabled on frozen port - this happens if
IRQ pending status isn't cleared in the IRQ router or controller)
exception messages get printed.

Skip reporting if ATA_EHI_QUIET is set.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This adds human-readable decoding of the ATA status and error registers
(similar to what drivers/ide does) as well as the SATA Serror register
to libata error handling output.  This prevents the need to pore
through standards documents to figure out the meaning of the bits
in these registers when looking at error reports.  Some bits that
drivers/ide decoded are not decoded here, since the bits are either
command-dependent or obsolete, and properly parsing them would add
too much complexity.
Signed-off-by: NRobert Hancock <hancockr@shaw.ca>

[edited slightly to make output a bit more symmetric]
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Hook PMP support into libata and enable it.  Connect SCR and probing
functions, and update ata_dev_classify() to detect PMP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

PMP always requires SRST to be enabled.  Also, hardreset reports
classification code from the first device when PMP is attached, not
from the PMP.  Update ata_eh_reset() such that followup softreset is
performed if the controller is PMP capable and the host link is being
reset.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

AN serves multiple purposes.  For ATAPI, it's used for media change
notification.  For PMP, for downstream PHY status change notification.
Implement sata_async_notification() which demultiplexes AN.

To avoid unnecessary port events, ATAPI AN is not enabled if PMP is
attached but SNTF is not available.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

If PMP itself becomes inaccessible while trying to link a downstream
link, spending time to recover the downstream link doesn't make any
sense.  Make EH skip retry and fail fast if -ERESTART is received.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_LFLAG_DISABLED.  The flag indicates the link is disabled
due to EH recovery failure.  While a link is disabled, no EH action is
taken on the link and suspend/resume become noop too.

This will be used by PMP links to manage failed links.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some PMP links are connected to internal pseudo devices which may come
and go depending on situation.  There's no reason to try hard to
recover them.  ATA_LFLAG_NO_RETRY tells EH to not retry if the device
attached to the link fails.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some links on some PMPs locks up on SRST and/or report incorrect
device signature.  Implement ATA_LFLAG_NO_SRST, ASSUME_ATA and
ASSUME_SEMB to handle these quirky links.  NO_SRST makes EH avoid
SRST.  ASSUME_ATA and SEMB forces class code to ATA and SEMB_UNSUP
respectively.  Note that SEMB isn't currently supported yet so the
_UNSUP variant is used.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ap->nr_active_links (the number of links with active qcs),
ap->excl_link (pointer to link which can be used by ->qc_defer and is
cleared when a qc with ATA_QCFLAG_CLEAR_EXCL completes), and
ata_link_active().

These can be used by ->qc_defer() to implement proper command
exclusion.  This set of helpers seem enough for both sil24 (ATAPI
exclusion needed) and cmd-switching PMP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make a number of functions from libata-core.c and libata-eh.c global
to libata (drivers/ata/libata.h).  These will be used by PMP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Consider newly found class code while revalidating.  PMP resetting
always results in valid class code and issuing PMP commands to
ATA/ATAPI device isn't very attractive.  Add @new_class to
ata_dev_revalidate() and check class code for revalidation.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

EH is sometimes repeated without any error or action.  For example,
this happens when probing IDENTIFY fails because of a phantom device.
In these cases, all the repeated EH does is making sure there is no
unhandled error or pending action and return.  This repeation is
necessary to avoid losing any event which occurred while EH was in
progress.

Unfortunately, this dry run causes annonying "EH pending after
completion" message.  This patch moves the repeat reporting into
ata_eh_report() such that it's more compact and skipped on dry runs.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Mikael Pettersson <mikep@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Currently, port configuration reporting has the following problems.

* iomapped address is reported instead of raw address
* report contains irrelevant fields or lacks necessary fields for
  non-SFF controllers.
* host->irq/irq2 are there just for reporting and hacky.

This patch implements and uses ata_port_desc() and
ata_port_pbar_desc().  ata_port_desc() is almost identical to
ata_ehi_push_desc() except that it takes @ap instead of @ehi, has no
locking requirement, can only be used during host initialization and "
" is used as separator instead of ", ".  ata_port_pbar_desc() is a
helper to ease reporting of a PCI BAR or an offsetted address into it.

LLD pushes whatever description it wants using the above two
functions.  The accumulated description is printed on host
registration after "[S/P]ATA max MAX_XFERMODE ".

SFF init helpers and ata_host_activate() automatically add
descriptions for addresses and irq respectively, so only LLDs which
isn't standard SFF need to add custom descriptions.  In many cases,
such controllers need to report different things anyway.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Update ata_eh_autopsy(), ata_eh_report(),
ata_eh_revalidate_and_attach() and ata_eh_recover() to deal with PMP
links.  ata_eh_autopsy() and ata_eh_report() updates are
straightforward.  They just repeat the same operation over all
configured links.  The only change to ata_eh_revalidate_and_attach()
is avoiding calling ->cable_select() on non-host ports.

ata_eh_recover() update is more complex as it first processes all
resets and then performs the rest.  This is necessary as thawing with
some links in unknown state can be dangerous.  ehi->action is cleared
on successful recovery of a link to avoid repeating recovery due to
failures in other links.

ata_eh_recover() iterates over only PMP links if PMP is attached, and,
on failure, the failing link is returned in @failed_link instead of
disabling devices directly.  These are to integrate ata_eh_recover()
into PMP EH later.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Update ata_scsi_error() to handle PMP links.  As error conditions can
occur on both host and PMP links, __ata_port_for_each_link() is used.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ata_link_abort().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make the following functions deal with ata_link instead of ata_port.

* ata_set_mode()
* ata_eh_autopsy() and related functions
* ata_eh_report() and related functions
* suspend/resume related functions
* ata_eh_recover() and related functions
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make reset methods and related functions deal with ata_link instead of
ata_port.

* ata_do_reset()
* ata_eh_reset()
* all prereset/reset/postreset methods and related functions

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make ata_eh_about_to_do() and ata_eh_done() deal with ata_link instead
of ata_port.

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make the following PHY-related functions to deal with ata_link instead
of ata_port.

* sata_print_link_status()
* sata_down_spd_limit()
* ata_set_sata_spd_limit() and friends
* sata_link_debounce/resume()
* sata_scr_valid/read/write/write_flush()
* ata_link_on/offline()

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Multiple links and different number of devices per link should be
considered to iterate over links and devices.  This patch implements
and uses link and device iterators - ata_port_for_each_link() and
ata_link_for_each_dev() - and ata_link_max_devices().

This change makes a lot of functions iterate over only possible
devices instead of from dev 0 to dev ATA_MAX_DEVICES.  All such
changes have been examined and nothing should be broken.

While at it, add a separating comment before device helpers to
distinguish them better from link helpers and others.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Introduce ata_link.  It abstracts PHY and sits between ata_port and
ata_device.  This new level of abstraction is necessary to support
SATA Port Multiplier, which basically adds a bunch of links (PHYs) to
a ATA host port.  Fields related to command execution, spd_limit and
EH are per-link and thus moved to ata_link.

This patch only defines the host link.  Multiple link handling will be
added later.  Also, a lot of ap->link derefences are added but many of
them will be removed as each part is converted to deal directly with
ata_link instead of ata_port.

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>