* Add an extra argument to ide_max_dma_mode() for passing requested transfer
  mode.  Use it as an upper limit when finding the best DMA for device/host.

* Rename ide_max_dma_mode() to ide_find_dma_mode() and at the same time add
  ide_max_dma_mode() wrapper which passes XFER_UDMA_6 as a requested mode to
  ide_find_dma_mode().  Also add inline ide_find_dma_mode() version for
  CONFIG_BLK_DEV_IDEDMA=n case.

* Pass requested transfer mode from ide_find_dma_mode() to ide_get_mode_mask()
  to avoid false warning from eighty_ninty_three().

* Use ide_find_dma_mode() to limit the user requested transfer mode in
  ide_rate_filter().  Also limit the requested mode by host max PIO mode.


Above changes make ide_rate_filter() to:

* Clip desired transfer mode down if it is invalid (values 0x0F, 0x13-0x19
  and 0x25-0x39, values > 0x46 were already clipped down, same for values
  0x25-0x39 but iff UDMA was not supported by the host).

* Clip desired transfer mode down if it is currently unsupported by IDE core
  (PIO6 and MWDMA3-4, the latter were already clipped down but iff UDMA was
  not supported by the host).

* Clip desired transfer mode down according to the host capabilities
  (UDMA modes were already clipped down but MWDMA/SWDMA/PIO weren't,
  also ->atapi_dma flag was not respected).

* Clip desired transfer mode down according to the device capabilities
  (except PIO modes for now which require mode work) - shouldn't be a
  problem since ide_set_xfer_rate() is called _after_ device has accepted
  given transfer mode.

and also result in a number of host driver specific bugfixes:

* icside
  - clip unsupported PIO5 mode down
  - fix unsupported/invalid modes being set in drive->current_speed

* ide-cris
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - clip DMA modes down for ATAPI devices
  - fix BUG() on unsupported/invalid modes

* au1xxx-ide
  - clip unsupported PIO5, SWDMA0-2 and MWDMA0-2
    (if BLK_DEV_IDE_AU1XXX_MDMA2_DBDMA=n) modes down

* aec62xx
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - clip DMA modes down for ATAPI devices
  - fix 0x00 being programmed as PIO timing for unsupported/invalid modes
  - fix unsupported/invalid modes being set on the device

* alim15x3
  - clip DMA modes down for ATAPI devices (chipset revision == 0x20 only)
  - fix theoretical OOPS for 0x0F mode
  - fix unsupported/invalid modes being set on the device

* amd74xx
  - clip unsupported SWDMA0-2 (on COBRA_7401 revs <= 7) modes down
  - fix random PIO timings being set for unsupported/invalid modes
  - fix unsupported/invalid modes being set on the device

* atiixp
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix cached MWDMA mode being cleared for unsupported/invalid modes
  - fix PIO{0,2} timings being programmed for unsupported/invalid modes
  - fix theoretical OOPS for PIO5-6 and 0x0F modes
  - fix unsupported/invalid modes being set on the device

* cmd64x
  - clip unsupported SWDMA0-2 modes down

* cs5530
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix unsupported/invalid modes being set on the device
  - fix BUG() on unsupported/invalid modes
    (which happened if the device accepted the setting)

* cs5535
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix unsupported/invalid modes being set on the device
  - fix theoretical OOPS for PIO5-6 and 0x0F modes

* hpt34x
  - clip DMA modes down for ATAPI devices
  - fix invalid timings being programmed for unsupported/invalid modes
  - fix unsupported/invalid modes being set on the device

* hpt366
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix PIO0 timings being programmed for unsupported/invalid modes
  - fix DMA timings being cleared for MWDMA3-4 and 0x25-0x39 modes
  - fix unsupported/invalid modes being set on the device

* it8213
  - clip unsupported PIO5, SWDMA0-1 and MWDMA0 modes down

* it821x
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - clip DMA modes down for ATAPI devices
    (chipset in smart mode and revision 0x10 in pass-through mode)

* jmicron
  - clip unsupported SWDMA0-2 modes down
  - fix unsupported/invalid modes being set on the device

* pdc202xx_new
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix unsupported/invalid modes being set on the device

* pdc202xx_old
  - clip unsupported PIO5 mode down
  - fix incorrect timings being set for unsupported/invalid modes
  - fix unsupported/invalid modes being set on the device

* piix
  - clip unsupported PIO5, SWDMA0-1 and MWDMA0 modes down

* sc1200
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix unsupported/invalid modes being set on the device
  - fix BUG() on unsupported/invalid modes
    (which happened if the device accepted the setting)

* scc_pata
  - clip unsupported PIO5, SWDMA0-2 and MWDMA0-2 modes down

* serverworks
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix DMA/UDMA timings/settings being cleared for unsupported/invalid modes
  - fix unsupported/invalid modes being set on the device

* siimage
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - clip DMA modes down for ATAPI devices (SATA chipsets)

* sis5513
  - clip unsupported PIO5 mode down
  - fix BUG() on unsupported/invalid modes

* sl82c105
  - clip unsupported SWDMA0-2 modes down

* slc90e66
  - clip unsupported PIO5, SWDMA0-1 and MWDMA0 modes down

* tc86c001
  - clip unsupported PIO5 and SWDMA0-2 modes down
  - fix PIO0 timings being programmed for PIO5/0x0F/SWDMA0-2/0x13-0x19 modes
  - fix invalid 0x00 DMA timing being programmed for MWDMA3-4/0x25-0x39 modes
  - fix unsupported/invalid modes being set on the device

* triflex
  - clip unsupported PIO5 mode down

* via82cxxx
  - fix random PIO timings being set for unsupported/invalid modes
  - fix unsupported/invalid modes being set on the device

* pmac
  - clip unsupported PIO5 and SWDMA0-2 modes down

* cmd640/ht6560b
  - clip DMA modes down (if CONFIG_BLK_DEV_IDEDMA=y)
  - fix PIO5 being clipped to PIO4 (if CONFIG_BLK_DEV_IDEDMA=n)

* opti621
  - clip DMA modes down (if CONFIG_BLK_DEV_IDEDMA=y)
  - clip unsupported PIO4 to PIO3 (if CONFIG_BLK_DEV_IDEDMA=n)


While at it:

* Use ide_rate_filter() in cs5520.c::cs5520_tune_chipset().

* Remove no longer needed checks from hpt366.c::hpt3{6,7}x_tune_chipset().
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>