K 10
svn:author
V 3
jhb
K 8
svn:date
V 27
2007-12-10T20:14:16.000000Z
K 7
svn:log
V 754
- Add a workaround for the DMA bugs on some alpha chipsets that ATA DMA
  trips over often.  Specifically, in these chipsets DMA transfers that
  cross a page boundary result in data corruption.  The workaround is to
  not allow any DMA transfers for non-static DMA maps (i.e. "real"
  transfers as opposed to work areas allocated with bus_dmamem_alloc()) to
  cross a page in a single S/G element.  This behavior is enabled by
  setting 'busdma_pyxis_bug' to 1.
- Add a new tunable 'machdep.busdma_pyxis_bug' that can be used to enable
  the workaround from the loader.  This can be used to enable it on
  chipsets where we don't automatically enable it.
- Auto-enable the workaround for buggy PYXIS 1 chipsets supported via
  cia(4).

PR:		alpha/75317

END