cvs commit: src/sys/alpha/alpha busdma_machdep.c src/sys/alpha/include md_var.h src/sys/alpha/pci cia.c

[John Baldwin]

jhb         2007-12-10 20:14:16 UTC

  FreeBSD src repository

  Modified files:        (Branch: RELENG_6)
    sys/alpha/alpha      busdma_machdep.c 
    sys/alpha/include    md_var.h 
    sys/alpha/pci        cia.c 
  Log:
  - 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
  
  Revision   Changes    Path
  1.51.2.3   +23 -6     src/sys/alpha/alpha/busdma_machdep.c
  1.23.10.1  +1 -0      src/sys/alpha/include/md_var.h
  1.44.2.1   +1 -0      src/sys/alpha/pci/cia.c