cvs commit: src/sys/dev/acpica acpi_pci_link.c

[Nate Lawson]

njl         2004-08-05 06:54:16 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/acpica       acpi_pci_link.c 
  Log:
  Work around non-compliant BIOS PCI link devices.  Some systems have the
  following behavior:
  
  * Link devices return invalid status (_STA) values.  The results are very
    unreliable -- sometimes never present.  Just ignore the status and pick
    the best configuration from _PRS.
  
  * Link devices return invalid current settings (_CRS).  Even after setting
    the link value, many systems still return a different setting for _CRS.
    When setting an IRQ, don't bother to check _CRS to see if we succeeded.
    Note that we still check _CRS before routing and this should be addressed
    as well.
  
  Since this is a sensitive area, leave the old behavior accessible via
  uncommenting the define for ACPI_OLD_PCI_LINK at the top of the file.  Once
  this has been thoroughly tested, this option and the code it covers will
  be removed.
  
  Thanks to Len Brown at Intel for informing us of these issues as he worked
  around them in Linux.
  
  Revision  Changes    Path
  1.17      +31 -0     src/sys/dev/acpica/acpi_pci_link.c