[haiku-development] Intel Enhanced Speedstep Driver

  • From: Clemens zeidler <clemens.zeidler@xxxxxxxxxxxxxx>
  • To: "haiku-development@xxxxxxxxxxxxx" <haiku-development@xxxxxxxxxxxxx>
  • Date: Fri, 09 Jan 2009 23:38:45 +0100

Hi,

in the previous acpi thread I mention that I like to write a acpi
speedstep driver. The problem is my CPU doesn't publish the frequence
states correct :-( so I only wrote a "normal" speedstep driver. My driver
still depends on acpi but it only ask the acpi busmanager for the cpu
device node. The driver is mostly a port of the bsd driver and suport 70
different (older) intel CPU's.

Also there is a patch for a preferences app where you can set the current
cpu state or choose a dynamic policy depending on the current cpu usage. A
status view for desktop and deskbar is also provided by the preferences
app.

I notice that when I step down the CPU frequency the HAIKU time runs
slower. The same problem also exist in BeOS and I already ran into it when
I wrote a
speedstep driver for BeOS. Michael Lotz wrote a nice article about this
timing problem:
http://beos.mlotz.ch/documents/cpu_fix.html
Michael is it still the same thing in HAIKU?

Could somebody look into the patch/ apply it?
For testing the driver you have to enable acpi and add the driver and the
preferences app to the image.

cheers,
        Clemens

Other related posts: