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 <[email protected]>
Cc: Alan Cox <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
1 file changed