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

[Nate Lawson]

njl         2005-10-25 21:15:47 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/acpica       acpi_cpu.c 
  Log:
  If we're trying to use C2/3 and reads from the register are returning
  immediately, back off to the next higher Cx sleep state.  Some machines
  with a Via chipset report a valid C3 but a register read doesn't actually
  halt the CPU.  This would cause the machine to appear unresponsive as it
  repeatedly called cpu_idle() which immediately returned.  Causing interrupts
  (i.e. by pressing the power button) would cause the system to make forward
  progress, showing that it wasn't actually hung.
  
  Also, enable interrupts a little earlier.  We don't need them disabled
  to calculate the delta time for the read.
  
  Reported by:    silby
  MFC after:      2 weeks
  
  Revision  Changes    Path
  1.59      +24 -3     src/sys/dev/acpica/acpi_cpu.c