libata: fix ata_acpi_gtm_xfermask()

ata_acpi_gtm_xfermask() as separated out from pacpi_discover_modes()
has various bugs.  Fix them.

* The wrong comparison operator is used when finding for matching
  cycle resulting totally bogus result.

* With the comparion operator fixed, boundary condtion handling is
  clumsy.

* Setting of any DMA mask bit set all bits in PIO mask.

* MWDMA and UDMA blocks are swapped.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Tejun Heo 2007-12-18 16:33:04 +09:00 committed by Jeff Garzik
commit 5df91a25df