Second-generation Promise SATA controllers have an ASIC bug
which can trigger if the last PRD entry is larger than 164 bytes,
resulting in intermittent errors and possible data corruption.

Work around this by replacing calls to ata_qc_prep() with a
private version that fills the PRD, checks the size of the
last entry, and if necessary splits it to avoid the bug.
Also reduce sg_tablesize by 1 to accommodate the new entry.

Tested on the second-generation SATA300 TX4 and SATA300 TX2plus,
and the first-generation PDC20378.

Thanks to Alexander Sabourenkov for verifying the bug by
studying the vendor driver, and for writing the initial patch
upon which this one is based.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
--
Changes since previous version:
* use new PDC_MAX_PRD constant to initialise sg_tablesize

 drivers/ata/sata_promise.c |   87 ++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 83 insertions(+), 4 deletions(-)
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

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>

It was always set to ata_port_disable().  Removed the hook, and replaced
the very few ap->ops->port_disable() callsites with direct calls to
ata_port_disable().
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* ->irq_ack() is redundant to what the irq handler already
  performs... chk-status + irq-clear.  Furthermore, it is only
  called in one place, when screaming-irq-debugging is enabled,
  so we don't want to bother with a hook just for that.

* ata_dummy_irq_on() is only ever used in drivers that have
  no callpath reaching ->irq_on().  Remove .irq_on hook from
  those drivers, and the now-unused ata_dummy_irq_on()
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>

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>

This patch corrects sata_promise to classify FastTrack TX4200
(DID 3515/3519) as a second-generation chip. Promise's partial-
source FT TX4200 driver confirms this classification.

Treating it as a first-generation chip causes several problems:
1. Detection failures. This is a recent regression triggered by
   the hotplug-enabling changes in 2.6.23-rc1.
2. Various "failed to resume link for reset" warnings.

This patch fixes <http://bugzilla.kernel.org/show_bug.cgi?id=8936>.

Thanks to Stephen Ziemba for reporting the bug and for testing the fix.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Tested-by: NStephen Ziemba <sziemba@ecn.purdue.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Convert ->scr_read/write callbacks to return error code to better
indicate failure.  This will help handling of SCR_NOTIFICATION.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch enables hotplugging of SATA devices in the
sata_promise driver. It's been tested successfully on
both first- and second-generation Promise SATA chips:
SATA150 TX2plus, SATAII150 TX2plus, SATAII150 TX4,
SATA300 TX2plus, and SATA300 TX4.

The only quirk I've seen is that hotplugging (insertion)
on the first-generation SATA150 TX2plus requires a lengthier
EH sequence than on the second-generation chips.
On the second-generation chips a simple soft reset seems
to suffice, but on the first-generation chip there's a
"port is slow to respond" after the initial soft reset,
after which libata issues a hard reset, and then the
device is recognised.

The hotplug checks are high up in the interrupt handling
path, not deep down in error_intr as in ahci/sata_sil24.
That's because the chip doesn't signal hotplug status changes
in the per-port status register: instead a global register
contains hotplug control and status flags for all ports.
I considered following the ahci/sata_sil24 structure, but
that would have required non-trivial changes to the interrupt
handling path, so I chose to keep the hotplug changes simple
and unobtrusive.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
--
This patch depends on the "sata_promise: cleanups" patch.

Changes since the previous version (posted June 19):
- Correct pdc_interrupt() to increment 'handled' also in
  the hotplug case. This prevents IRQ_NONE from being
  returned when an interrupt only has hotplug events to
  handle, which could confuse the kernel's IRQ machinery.
- Added testing on the SATAII150 TX4.

 drivers/ata/sata_promise.c |   41 ++++++++++++++++++++++++++++++++++++-----
 1 files changed, 36 insertions(+), 5 deletions(-)
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* Use ATA_UDMA*
* Remove FIXME notations that once served to remind us to verify
  that these were indeed the correct UDMA masks.  They are.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch applies some trivial cleanups to sata_promise:
- repair whitespace damage
- correct comment at board_2057x_pata definition
- pull SATAII TX4 support code out to separate functions
- rename ata_nr to ata_no for consistency with libata's port_no
- remove some init-time debug printks (requested by Jeff)

This patch should cause no behavioural changes, except for
the removed printks.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
--
 drivers/ata/sata_promise.c |   56 ++++++++++++++++++---------------------------
 1 files changed, 23 insertions(+), 33 deletions(-)
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NJeff Garzik <jeff@garzik.org>

sata_promise uses two different command modes - packet and TF.  Packet mode
is intelligent low-overhead mode while TF is the same old taskfile
interface.  As with other advanced interface (ahci/sil24),
ATA_TFLAG_POLLING has no effect in packet mode.  However, PIO commands are
issued using TF interface in polling mode, so pdc_interrupt() considers
interrupts spurious if ATA_TFLAG_POLLING is set.

This is broken for polling NODATA commands because command is issued using
packet mode but the interrupt handler ignores it due to ATA_TFLAG_POLLING.
Fix pdc_qc_issue_prot() such that ATA/ATAPI NODATA commands are issued
using TF interface if ATA_TFLAG_POLLING is set.

This patch fixes detection failure introduced by polling SETXFERMODE.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Acked-by: NMikael Pettersson <mikpe@it.uu.se>
Acked-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A stray comma makes all the difference.  Change to '|' as these flags
should be or'd together.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

There is a known problem with sata_promise on SATAII-150/300 TX4
controller cards: it enumerates drives in an order that differs
from the port numbers printed on the controller cards. However,
Promise's BIOS and Linux driver both get the order right.

I investigated Promise's Linux driver (v1.01.0.23), and found
that it explicitly changes the mapping from logical port number
to ATA engine MMIO address on the SATAII TX4 cards. It does this
on all SATAII TX4 cards, without inspecting revision etc. The
SATAII TX2plus cards continue to use the same mapping that was
used for the first-generation chips.

This patch updates sata_promise to use the new port number to
ATA engine mapping on SATAII TX4 cards, which fixes the drive
enumeration order problem on those cards. Tested on several
1st and 2nd generation TX2plus and TX4 chips.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The sata_promise error decode update changed pdc_host_intr()
to return and not complete the qc after detecting an error.
Unfortunately not completing the qc:s causes them to always
time out on error, which is wrong and has nasty side-effects.

This patch updates pdc_error_intr() to call ata_port_abort(),
similar to ahci and sata_sil24. Doing this is important as it
makes EH see the original error and not a bogus timeout.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Convert sata_via and sata_promise to new init model.  Both controllers
can have combined configuration (SATA + PATA) and used twisted
initialization method (modifying port in ->port_start) to overcome
probe_ent limitations.

This patch converts both drivers to new init model in which such
configuration is natively supported.

* promise: Combined pata port now uses separate port_info entry right
  after the sata counterpart entry.

* promise: Controller configuration is discerned using ap->flags.
  This simplifies init path and makes it look more like other LLDs.

* via: Both SATA and PATA ports in vt6421 are represented in their
  own port_info structure.

Tested on PDC20375 (SATA150 TX2plus) [105a:3375] and PDC40775 (SATA
300 TX2plus) [105a:3d73].  Couldn't test via cuz my c3 won't boot the
current kernel.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

->post_internal_cmd is simplified EH for internal commands.  Its
primary mission is to stop the controller such that no rogue memory
access or other activities occur after the internal command is
released.  It may provide error diagnostics by setting qc->err_mask
but this hasn't been a requirement.

To ignore SETXFER failure for CFA devices, libata needs to know
whether a command was failed by the device or for any other reason.
ie. internal command needs to get AC_ERR_DEV right.

This patch makes the following changes to AC_ERR_DEV handling and
->post_internal_cmd semantics to accomodate this need and simplify
callback implementation.

1. As long as the correct bits in the result TF registers are set,
   there is no need to set AC_ERR_DEV explicitly.  libata EH core
   takes care of that for both normal and internal commands.

2. The only requirement for ->post_internal_cmd() is to put the
   controller into quiescent state.  It needs not to set any err_mask.

3. ata_exec_internal_sg() performs minimal error analysis such that
   AC_ERR_DEV is automatically set as long as result_tf is filled
   correctly.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Promise ATA ports should always be reset by pdc_reset_port()
when errors are detected, but the recent error reason decoding
update to sata_promise replaced that reset with a freeze.

This patch changes the error detection to do a reset again.
This makes the error decoding update safer, as it now only
adds error decoding without changing any other behaviour.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch adds much needed error reason decoding and
reporting to sata_promise. It's simplistic but should
log all relevant error info the controller provides.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch changes sata_promise so that the PATA ports
on TX2plus chips are bound to the pdc_pata_ops structure.
This means that operations called from the SATA ops
structures don't need any SATA-vs-PATA tests any more.
Instead, operations that depend on a port being SATA or
PATA are separated into different procedures.

* pdc_cable_type() is split into a PATA version and a
  SATA version
* pdc_error_handler() is split into a PATA version and a
  SATA version, that both call a common version after
  setting up the `hardreset' function pointer
* pdc_old_check_atapi_dma() is now only used for SATAI
  ports, so is renamed to pdc_old_sata_check_atapi_dma()
  and simplified
* pdc_sata_scr_{read,write}() are now only used for SATA
  ports, so their is-not-SATA tests are removed
* pdc_port_start() is split into three procedures: a wrapper
  which performs the ->ops adjustment on TX2plus PATA ports,
  a procedure with the common code, and a procedure with
  the SATA-specific code (this bit might be cleaned up by
  Tejun's new init model)

Tested on 20619, 20575, and 20775 chips.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The recent change which moved cable detection from
pdc_pre_reset() to the new ->cable_detect hook only
added the hook for SATAII chips, leaving SATAI chips
and the 20619 without the hook. Fixed by this patch.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NAlan Cox <number6@the-village.bc.nu>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Bump versions based on changes submitted during 2.6.21 merge window.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Each place in pdc_ata_init_one() that initialises a SATA
port first calls pdc_ata_setup_port(), and then manually
assigns the port's ->scr_addr. Simplify the code by extending
pdc_ata_setup_port() to also handle scr_addr initialisation;
for PATA ports we pass NULL as scr_addr.

The initialisation of the PATA-only 20619 redundantly set
up scr_addr for the ports. Remove this.

Tested on 20619, 20575, and 20775 chips.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

When I merged my 20619 new EH conversion with #libata-upstream
I had to manually resolve a conflict, and inadvertently lost
pdc_pata_ops' ->post_internal_cmd binding. Corrected by this patch.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch updates the sata_promise driver to use new-style
libata error handling for 20619 (TX4000) chips. sata_promise
already uses new EH for the other chips it supports, so the
patch is quite simple:

* remove ->phy_reset and ->eng_timeout ops from pdc_pata_ops,
  and instead bind ->freeze, ->thaw, ->error_handler, and
  ->post_internal_cmd to existing new EH functions
* drop ATA_FLAG_SRST from board_20619's flags
* remove now unused pdc_pata_phy_reset() and pdc_eng_timeout()

Tested on a TX4000 with both modern working disks and old/quirky
disks. Also used a CD-RW drive to test reading and writing CDs.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch fixes an oversight which caused sata_promise to
not perform cable detection on the TX2plus chips' PATA ports.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch is against each libata driver.

Two IRQ calls are added in ata_port_operations.
- irq_on() is used to enable interrupts.
- irq_ack() is used to acknowledge a device interrupt.

In most drivers, ata_irq_on() and ata_irq_ack() are used for
irq_on and irq_ack respectively.

In some drivers (ex: ahci, sata_sil24) which cannot use them
as is, ata_dummy_irq_on() and ata_dummy_irq_ack() are used.
Signed-off-by: NKou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: NAkira Iguchi <akira2.iguchi@toshiba.co.jp>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Convert libata core layer and LLDs to use iomap.

* managed iomap is used.  Pointer to pcim_iomap_table() is cached at
  host->iomap and used through out LLDs.  This basically replaces
  host->mmio_base.

* if possible, pcim_iomap_regions() is used

Most iomap operation conversions are taken from Jeff Garzik
<jgarzik@pobox.com>'s iomap branch.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Update libata LLDs to use devres.  Core layer is already converted to
support managed LLDs.  This patch simplifies initialization and fixes
many resource related bugs in init failure and detach path.  For
example, all converted drivers now handle ata_device_add() failure
gracefully without excessive resource rollback code.

As most resources are released automatically on driver detach, many
drivers don't need or can do with much simpler ->{port|host}_stop().
In general, stop callbacks are need iff port or host needs to be given
commands to shut it down.  Note that freezing is enough in many cases
and ports are automatically frozen before being detached.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Merge order left qc->nsect usage in sata_promise dangling.  Kill it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch extends sata_promise to handle ATAPI_NODATA
commands internally. However, commands destined to
ATA_DFLAG_CDB_INTR devices are excluded from this and
continue to be returned to libata.

Concrete changes:
- pdc_atapi_dma_pkt() is renamed to pdc_atapi_pkt(), and is
  extended to set up correct headers for NODATA packets
- pdc_qc_prep() calls pdc_atapi_pkt() for ATAPI_NODATA
- pdc_host_intr() handles ATAPI_NODATA
- pdc_qc_issue_prot() sends ATAPI_NODATA packets via the
  chip's packet mechanism, except for CDB_INTR devices

Tested on first- and second-generation chips, SATAPI and PATAPI,
with no observable regressions.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch (against libata #upstream + the ATAPI cleanup patch)
reimplements sata_promise's ATAPI support to format ATAPI DMA
commands as normal packets, and to issue them via the hardware's
normal packet machinery.

It turns out that the only reason for issuing ATAPI DMA
commands via the pdc_issue_atapi_pkt_cmd() procedure was to
perform two interrupt-fiddling steps for ATA_DFLAG_CDB_INTR
devices. But these steps aren't needed because sata_promise
sets ATA_FLAG_PIO_POLLING, which disables DMA for those devices.
The remaining steps can easily be done in ATA taskfile packets.

Concrete changes:
- pdc_atapi_dma_pkt() is extended to program all packet setup
  steps, and not just contain the CDB; the sequence of steps
  exactly mirrors what pdc_issue_atapi_pkt_cmd() did
- pdc_atapi_dma_pkt() needed more parameters: simplify it by
  just passing 'qc' and having it extract the data it needs
- pdc_issue_atai_pkt_cmd() and its two helper procedures
  pdc_wait_for_drq() and pdc_wait_on_busy() are removed

Tested on first- and second-generation chips, SATAPI and PATAPI,
with no observable regressions.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Here's a cleanup for yesterday's sata_promise ATAPI patch:
- add and use a symbolic constant for the altstatus register
- check return status from ata_busy_wait()
- add missing newline in a warning printk()
- update comment in pdc_issue_atapi_pkt_cmd() to clarify
  that the maybe-wait-for-INT issue cannot occur in the
  current driver, but may occur if the driver starts issuing
  ATAPI non-DMA commands as PDC packets
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch adds ATAPI support to the sata_promise driver.
This has been tested on both first- and second-generation
chips (20378 and 20575), and with both SATAPI and PATAPI
devices. CD-writing works.

SATAPI DMA works on second-generation chips, but on
first-generation chips SATAPI is limited to PIO due
to what appears to be HW limitations.
PATAPI DMA works on both first- and second-generation
chips, but requires the separate PATA support patch
before it can be used on TX2plus chips.

The functional changes to the driver are:
- remove ATA_FLAG_NO_ATAPI from PDC_COMMON_FLAGS
- add ->check_atapi_dma() operation to enable DMA for bulk data
  transfers but force PIO for other ATAPI commands; this filter
  is from Promise's driver and largely matches pata_pdc207x.c
- use a more restrictive ->check_atapi_dma() on first-generation
  chips to force SATAPI to always use PIO
- add handling of ATAPI protocols to pdc_qc_prep(), pdc_host_intr(),
  and pdc_qc_issue_prot(): ATAPI_DMA is handled by the driver
  while non-DMA protocols are handed over to libata generic code
- add pdc_issue_atapi_pkt_cmd() to handle the initial steps in
  issuing ATAPI DMA commands before sending the actual CDB;
  this procedure was ported from Promise's driver
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch implements a simple way of setting up per-port
flags on the SATA+PATA Promise TX2plus chips, which is a
prerequisite for supporting the PATA port on those chips.

It is based on the observation that ap->flags isn't really
used until after ->port_start() has been invoked. So it
places the "exceptional" per-port flags array in the driver's
private host structure, and uses it in ->port_start() to
finalise the port's flags.

This patch obsoletes the #promise-sata-pata branch included
in the #all branch.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch converts sata_promise to use new-style libata error
handling on Promise SATA chips, for both SATA and PATA ports.

* ATA_FLAG_SRST is no longer set
* ->phy_reset is no longer set as it is unused when ->error_handler
   is present, and pdc_sata_phy_reset() has been removed
* pdc_freeze() masks interrupts and halts DMA via PDC_CTLSTAT
* pdc_thaw() clears interrupt status in PDC_INT_SEQMASK and then
  unmasks interrupts in PDC_CTLSTAT
* pdc_error_handler() reinitialises the port if it isn't frozen,
  and then invokes ata_do_eh() with standard {s,}ata reset methods
* pdc_post_internal_cmd() resets the port in case of errors
* the PATA-only 20619 chip continues to use old-style EH:
  not by necessity but simply because I don't have documentation
  for it or any way to test it

Since the previous version pdc_error_handler() has been rewritten
and it now mostly matches ahci and sata_sil24. In case anyone
wonders: the call to pdc_reset_port() isn't a heavy-duty reset,
it's a light-weight reset to quickly put a port into a sane state.

The discussion about the PCI flushes in pdc_freeze() and pdc_thaw()
seemed to end with a consensus that the flushes are OK and not
obviously redundant, so I decided to keep them for now.

This patch was prepared against 2.6.19-git7, but it also applies
to 2.6.19 + libata #upstream, with or without the revised sata_promise
cleanup patch I recently submitted.

This patch does conflict with the #promise-sata-pata patch:
this patch removes pdc_sata_phy_reset() while #promise-sata-pata
modifies it. The correct patch resolution is to remove the function.

Tested on 2037x and 2057x chips, with PATA patches on top and disks
on both SATA and PATA ports.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>