MFC r222142:

MFC r222142:
  Datasheet says vge(4) controllers support DAC but it seems that's
  not true on old PCI based controllers.  DAC configuration is read
  from EEPROM in device reset phase and driver can override DAC
  configuration.  However I guess there is an undocumented reason why
  EEPROM configuration does not enable DAC so do not blindly override
  DAC configuration.  Recent PCIe based controllers are supposed to
  support 64bit DMA so allow 64bit DMA only on PCIe based controllers.

  PR:	kern/157184

git-svn-id: svn://svn.freebsd.org/base/stable/8@222367 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f