Re: cpufreq est and Enhanced Sleep (Cx) States for Intel Core and above

On Wed, Dec 13, 2006 at 12:14:55PM -0500, Stephane E. Potvin wrote:

  Adam McDougall wrote:
  >On Sat, Dec 09, 2006 at 07:29:23PM -0500, Adam McDougall wrote:
  >
  >  Another thing I wish could work is the Enhanced cpu Sleep States;
  >  this Dell Latitude D820 laptop only sees C1 although the document
  >  above indicates it should probably support 4 unique states.  Is 
  >  there a way I can debug and/or fix this?  I can post dumps of the
  >  acpi stuff and/or verbose boot logs if it would be helpful.  
  >  
  >  Thanks
  >  _______________________________________________
  >
  >I am attaching my asl and dsdt acpi dumps incase someone knows for
  >something to look for as for why it thinks I only have C1, unless 
  >its related to the speed control problem above.  
  >
  Hi Adam,
  
  It's only finding the C1 state for various reasons that you'll find 
  described in some details in the following email that I send to the acpi 
  mailing list in June this year. The major reason being that the acpi cpu 
  driver does not support well multiprocessor systems.
  
  http://docs.freebsd.org/cgi/getmsg.cgi?fetch=116103+0+archive/2006/freebsd-acpi/20060611.freebsd-acpi
  
  The email also included a patch to add support for multiprocessor 
  systems to the acpi cpu driver. I've not updated the patch since then so 
  it might or might not apply cleanly to a recent current.
  
  Steph

I didn't get around to trying that patch, but I have tried -current 
after code was committed, including as late as Feb 11.  It seems to work,
but if both of my cpus are allowed to enter C3 state, my laptop
clock stops advancing (unless you are causing activity) and the performance
gets very choppy, including mouse cursor halting for a second or two, etc.
Typing or moving the mouse seems to nudge the system into crawling along,
but if I leave it alone, timing loops stall.  I could do a while loop with
a sleep on the command line and time just doesn't advance on its own, and
the clock in Gnome would halt.  My laptop is using the Hpet timer, but it
doesn't seem to make a difference if I use sysctl to try ACPI-fast or i8254.

Where should I start to help figure this out?