The DMA support for RAID mode broke after:

	commit 71ef51cc
	Author: Jens Axboe <axboe@suse.de>
	Date:   Fri Jul 28 09:02:17 2006 +0200

	    [PATCH] it821x: fix ide dma setup bug

	    Only enable dma for a valid speed setting.

	    Signed-off-by: Jens Axboe <axboe@suse.de>

	commit 0a8348d0
	Author: Jens Axboe <axboe@suse.de>
	Date:   Fri Jul 28 08:58:26 2006 +0200

	    [PATCH] ide: if the id fields looks screwy, disable DMA

	    It's the safer choice. Originally due to a bug in itx821x, but a
	    generally sound thing to do.

	    Signed-off-by: Jens Axboe <axboe@suse.de>

However it worked by pure luck before Jens' fixes: bogus ide_dma_enable()
usage in it821x driver combined with loosy check in ide_dma_verbose() allowed
the hardware to operate in DMA mode.  When these problems were fixed the DMA
support broke...

The source root for the regression turned out to be that the it821x.c code
was clearing too much of id->field_valid.  The IDE core code was using the
original value of id->field_valid to do the tuning but later DMA got disabled
in ide_dma_verbose() because of the incorrect id->field_valid fixup.  Fix it.

While at it:

* Do fixup() after probing the drives but before tuning them (which is also
  OK w.r.t. ide_undecoded_slave() fixup).  This change fixes device IDENTIFY
  data to be consistent before/after the tuning and allows us to remove extra
  re-tuning of drives from it821x_fixups().

* Fake MWDMA0 enabled/supported bits in IDENTIFY data if the device has
  DMA capable bit set (this is just to tell the IDE core that DMA is
  supported since it821x firmware takes care of DMA mode programming).

* Don't touch timing registers and don't program transfer modes on devices
  et all when in RAID mode - depend solely on firmware to do the tuning
  (as suggested by Alan Cox and done in libata pata_it821x driver).

Thanks for testing the patch goes out to Thomas Kuther.

Cc: Thomas Kuther <gimpel@sonnenkinder.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Use ide_tune_dma() in ide-cris/it821x/pdc202xx_old/serverworks drivers.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Depends on the "ide: fix UDMA/MWDMA/SWDMA masks" patch.

* add ide_hwif_t.udma_filter hook for filtering UDMA mask
  (use it in alim15x3, hpt366, siimage and serverworks drivers)
* add ide_max_dma_mode() for finding best DMA mode for the device
  (loosely based on some older libata-core.c code)
* convert ide_dma_speed() users to use ide_max_dma_mode()
* make ide_rate_filter() take "ide_drive_t *drive" as an argument instead
  of "u8 mode" and teach it to how to use UDMA mask to do filtering
* use ide_rate_filter() in hpt366 driver
* remove no longer needed ide_dma_speed() and *_ratemask()
* unexport eighty_ninty_three()

v2:
* rename ->filter_udma_mask to ->udma_filter
  [ Suggested by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]

v3:
* updated for scc_pata driver (fixes XFER_UDMA_6 filtering for user-space
  originated transfer mode change requests when 100MHz clock is used)
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* limit max PIO mode to PIO4, this driver doesn't support PIO5 and attempt
  to setup PIO5 by it821x_tuneproc() could result in incorrect PIO timings
  + incorrect base clock being set for controller in the passthrough mode

* move code limiting max PIO according to the pair device capabilities from
  config_it821x_chipset_for_pio() to it821x_tuneproc() so the check is also
  applied for mode change requests coming through ->tuneproc and ->speedproc
  interfaces

* set device speed in it821x_tuneproc()

* in it821x_tune_chipset() call it821x_tuneproc() also if the controller is
  in the smart mode (so the check for pair device max PIO is done)

* rename it821x_tuneproc() to it821x_tune_pio(), then add it821x_tuneproc()
  wrapper which does the max PIO mode check;  it worked by the pure luck
  previously, pio[4] and pio_want[4] arrays were used with index == 255
  so random PIO timings and base clock were set for the controller in the
  passthrough mode, thankfully PIO timings and base clock were corrected
  later by config_it821x_chipset_for_pio() call (but it was not called for
  PIO-only devices during resume and for user requested PIO autotuning)

* remove config_it821x_chipset_for_pio() call from config_chipset_for_dma()
  as the driver sets ->autotune to 1 and ->tuneproc does the proper job now

* convert the last user of config_it821x_chipset_for_pio() to use
  it821x_tuneproc(drive, 255) and remove no longer needed function

While at it:

* fix few comments

* bump driver version
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* since ide_hwif_t.ide_dma_{host_off,off_quietly} always return '0'
  make these functions void and while at it drop "ide_" prefix
* fix comment for __ide_dma_off_quietly()
* make __ide_dma_{host_off,off_quietly,off}() void and drop "__" prefix

v2:
* while at it rename atiixp_ide_dma_host_off() to atiixp_dma_host_off(),
  sgiioc4_ide_dma_{host_off,off_quietly}() to sgiioc4_dma_{host_off,off_quietly}()
  and sl82c105_ide_dma_off_quietly() to sl82c105_dma_off_quietly()
  [ Noticed by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* add ide_set_dma() helper and make ide_hwif_t.ide_dma_check return
  -1 when DMA needs to be disabled (== need to call ->ide_dma_off_quietly)
   0 when DMA needs to be enabled  (== need to call ->ide_dma_on)
   1 when DMA setting shouldn't be changed
* fix IDE code to use ide_set_dma() instead if using ->ide_dma_check directly

v2:
* updated for scc_pata
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Only enable dma for a valid speed setting.
Signed-off-by: NJens Axboe <axboe@suse.de>

Missing variable initialisation would mean it would sometimes not put ATAPI
devices into DMA by default.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: <Jack.Lee@ite.com.tw>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NAlan Cox <alan@redhat.com>
Acked-by: NBartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NDeepak Saxena <dsaxena@plexity.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This lets you throw out the iteraid stuff that has ended up back in due
to stupid goings on in the IDE world. Its the same heavily tested code
shipped in Fedora/Red Hat products but without the other dependancies on
the Bartlomiej IDE layer.

Pre-requisite: the ide-disk patch I sent to handle pure LBA devices.

Obviously you lose things like hot unplug with the Bartlomiej IDE layer
at the moment but that won't matter to most users.

The patch does the following
- Add IT8211/12 to pci_ids.h
- Add Makefile/Kconfig entry
- Add it8212 driver

No core IDE code is touched by this diff

Embedded system testing and the ability to force raid mode off by David
Howells

Made possible by the ite reference code, documentation and also several
clarifications and pieces of assistance provided by ITE themselves
Signed-off-by: NAlan Cox <alan@redhat.com>
Acked-by: NBartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>