With ATAPI transfer chunk size properly programmed, libata PIO HSM
should be able to handle full spurious data chunks.  Also, it's a good
idea to suppress trailing data warning for misc ATAPI commands as
there can be many of them per command - for example, if the chunk size
is 16 and the drive tries to transfer 510 bytes, there can be 31
trailing data messages.

This patch makes the following updates to libata ATAPI PIO HSM
implementation.

* Make it drain full spurious chunks.

* Suppress trailing data warning message for misc commands.

* Put limit on how many bytes can be drained.

* If odd, round up consumed bytes and the number of bytes to be
  drained.  This gets the number of bytes to drain right for drivers
  which do 16bit PIO.

This patch is partial backport of improve-ATAPI-data-xfer patchset
pending for #upstream.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

On certain implementations, _GTF evaluation depends on preceding _STM
and both can be pretty picky about the configuration.  Using _GTM
result cached during controller initialization satisfies the most
neurotic _STM implementation.  However, libata evaluates _GTF after
reset during device configuration and the hardware state can be
different from what _GTF expects and can cause evaluation failure.

This patch adds dev->gtf_cache and updates ata_dev_get_GTF() such that
it uses the cached value if available.  Cache is cleared with a call
to ata_acpi_clear_gtf().

Because for SATA ACPI nodes _GTF must be evaluated after _SDD which
can't be done till IDENTIFY is complete, _GTF caching from
ata_acpi_on_resume() is used only for IDE ACPI nodes.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

_GTM fetches currently configured transfer mode while _STM configures
controller according to _GTM parameter and prepares transfer mode
configuration TFs for _GTF.  In many cases _GTM and _STM
implementations are quite brittle and can't cope with configuration
changed by libata.

libata does not depend on ATA ACPI to configure devices.  The only
reason libata performs _GTM and _STM are to make _GTF evaluation
succeed and libata also doesn't care about how _GTF TFs configure
transfer mode.  It overrides that configuration anyway, so from
libata's POV, it doesn't matter what value is feeded to _STM as long
as evaluation succeeds for _STM and following _GTF.

This patch adds dev->__acpi_init_gtm and store initial _GTM values on
host initialization before modified by reset and mode configuration.
If the field is valid, ata_acpi_init_gtm() returns pointer to the
saved _GTM structure; otherwise, NULL.

This saved value is used for _STM during resume and peek at
BIOS/firmware programmed initial timing for later use.  The accessor
is there to make building w/o ACPI easy as dev->__acpi_init doesn't
exist if ACPI is not enabled.

On driver detach, the initial BIOS configuration is restored by
executing _STM with the initial _GTM values such that the next driver
can also use the initial BIOS configured values.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

Make prink helpers format @lv together rather than prepending to the
format string as constant.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

* No internal function uses const ata_port.  Drop const from @ap.

* Make ata_acpi_stm() copy @stm before using it and change @stm to
  const.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

After an error condition, some ATAPI tape drives set DRQ=1 together
with ERR=1 when asking the host to transfer the CDB of the next packet
command (i.e. request sense).  This patch, a revised version of
Alan/Mark's previous patch, adds ATA_HORKAGE_STUCK_ERR to workaround
the problem by ignoring the ERR bit and proceed sending the CDB.

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mark Lord <liml@rtr.ca>
Signed-off-by: Tejun Heo <htejun@gmail.com>

This patch removes the following obsolete functions:
- libata-core.c: __sata_phy_reset()
- libata-core.c: sata_phy_reset()
- libata-eh.c: ata_qc_timeout()
- libata-eh.c: ata_eng_timeout()

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Tejun Heo <htejun@gmail.com>

One or two ancient drives predated the cable spec and didn't sent the
valid bits for the field. I had hoped to leave this out of libata as a
piece of historical annoyance but a recent CD drive shows the same bug so
we have to import support for it.

Same concept as Bartlomiej's changes old IDE except that as we have
centralised blacklists we can avoid keeping another private table of stuff

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff 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: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff 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:  Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>