This patch reimplements ACPI invocation such that, instead of
exporting ACPI details to the rest of libata, ACPI event handlers -
ata_acpi_on_resume() and ata_acpi_on_devcfg() - are used.  These two
functions are responsible for determining whether specific ACPI method
is used and when.

On resume, _GTF is scheduled by setting ATA_DFLAG_ACPI_PENDING device
flag.  This is done this way to avoid performing the action on wrong
device device (device swapping while suspended).

On every ata_dev_configure(), ata_acpi_on_devcfg() is called, which
performs _SDD and _GTF.  _GTF is performed only after resuming and, if
SATA, hardreset as the ACPI spec specifies.  As _GTF may contain
arbitrary commands, IDENTIFY page is re-read after _GTF taskfiles are
executed.

If one of ACPI methods fails, ata_acpi_on_devcfg() retries on the
first failure.  If it fails again on the second try, ACPI is disabled
on the device.  Note that successful configuration clears ACPI failed
status.

With all feature checks moved to the above two functions,
do_drive_set_taskfiles() is trivial and thus collapsed into
ata_acpi_exec_tfs(), which is now static and converted to return the
number of executed taskfiles to be used by ata_acpi_on_resume().  As
failures are handled properly, ata_acpi_push_id() now returns -errno
on errors instead of unconditional zero.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* Add missing LOCKING: and RETURNS: to function comment.

* Don't conditionalize warning messages with ata_msg_probe().  Print
  directly with KERN_WARNING.

* Drop duplicate debug messages.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch cleans up ata_acpi_exec_tfs() and its friends.

* Rename taskfile_array to ata_acpi_gtf and make it __packed as it's
  used as argument to ACPI method, and use pointer to ata_acpi_gtf and
  number of taskfiles to represent _GTF taskfiles instead of a pointer
  casted into unsigned long and byte count.  This makes argument
  re-checking in do_drive_set_taskfiles() unnecessary.

* Pointer in void * not in unsigned long.

* Clean up do_drive_get_GTF() error handling and make
  do_drive_get_GTF() return number of taskfiles on success, 0 if _GTF
  doesn't exist or doesn't contain valid ata.  -errno on other errors.

* Remove superflous check for acpi->buffer.pointer.

* Update taskfile_load_raw() such that printed messages look similar
  to the messages printed by ata_eh_report().

* s/do_drive_get_GTF/ata_dev_get_GTF/
  s/do_drive_set_taskfiles/ata_dev_set_taskfiles/
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* Add acpi_handle to ata_host and ata_port.  Rename
  ata_device->obj_handle to ->acpi_handle and move it above such that
  it doesn't get cleared on reconfiguration.

* Replace ACPI node association which ata_acpi_associate() which is
  called once during host initialization.  Unlike the previous
  implementation, ata_acpi_associate() uses ATA_FLAG_ACPI_SATA to
  choose between IDE or SATA ACPI hierarchy and uses simple child look
  up instead of recursive walk to match the nodes.  This is way safer
  and simpler.  Please read the following message for more info.

  http://article.gmane.org/gmane.linux.ide/17554Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Whether a controller needs IDE or SATA ACPI hierarchy is determined by
the programming interface of the controller not by whether the
controller is SATA or PATA, or it supports slave device or not.  This
patch adds ATA_FLAG_ACPI_SATA port flags which tells libata-acpi that
the port needs SATA ACPI nodes, and sets the flag for ahci and
sata_sil24.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch cleans up libata-acpi such that it looks similar to other
libata files.  This patch doesn't introuce any behavior changes.

* make libata-acpi functions take ata_device instead of ata_port +
  device index
* s/atadev/dev/
* de-indent local variable declarations
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

_GTF command is never ATA_PROT_ATAPI_NODATA whether the device is
ATAPI or not.  It's always ATA_PROT_NODATA.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Not yet ready to turn on ATA ACPI by default, for either PATA or SATA.

Also, rename the global-scope module parameter variable 'noacpi' to
something more libata-specific, reducing the potential for namespace
collision.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The ACPI specification states, and BIOS implementations depend on,
_STM being called before _GTF.

SATA does this, but PATA does not.  So for now, simply
prevent execution of _GTF on PATA devices.  Longer term we
should implement ACPI support for PATA devices in libata.
Signed-off-by: NKristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

For 2.6.20 it mostly used to just not work, for 2.6.21-rc it crashes, this
seems to be down to luck (bad or good). The libata-acpi code needs to
avoid doing PCI work on non-PCI devices. This is one hack although it's
not pretty and perhaps there is a "right" way to check if a struct device
* is PCI ?
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All drivers must implement this hook, otherwise ATA commands would go
nowhere (and a lot of other oopsen would appear as well).
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Merge order left libata-acpi and pata_scc with remainling usage of
ap->id.  Kill superflous id printing and substitute the remaining ones
with ap->print_id.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

I have reproduced the AE_AML_BUFFER_LIMIT exception mentioned in
<http://bugzilla.kernel.org/show_bug.cgi?id=7689> basing on the SSDT ASL
code and libata ata_acpi_push_id() code.  There is an oversight in
ata_acpi_push_id() causing the exception.  The following update fixes it:
Signed-off-by: NFiodor Suietov <fiodor.f.suietov@intel.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

_SDD (Set Device Data) is an ACPI method that is used to tell the
firmware what the identify data is of the device that is attached to
the port.  It is an optional method, and it's ok for it to be missing.
Because of this, we always return success from the routine that calls
this method, even if the execution fails.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>
(cherry picked from 39aa79e0a1f5f2e28aa341f035940746a98b45b1 commit)

_GTF is an acpi method that is used to reinitialize the drive.  It returns
a task file containing ata commands that are sent back to the drive to restore
it to boot up defaults.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>
(cherry picked from 9c69cab24b51a89664f4c0dfaf8a436d32117624 commit)