Re: PowerNow! frequency scaling causes stalls

From: Dick Streefland
Date: Tue Oct 04 2005 - 16:16:29 EST


spam@xxxxxxxxx (Dick Streefland) wrote:
| I have a new laptop with an AMD Mobile Sempron, and I'm experimenting
| with the PowerNow! frequency scaling. It seems to work, but on every
| frequency change, everything stalls for 3-4 seconds, even the X mouse
| pointer! Keyboard input seems to be buffered though. Is this normal?

I found out that the pauses only occur when the X server is running,
not when I work on the console, or remotely. I can easily reproduce
the problem by playing an mp3 file in a console with mpg321, and then
running burnK7 to force frequency scaling. Without X server running,
everything works fine, but when the X server is running, the music
skips on frequency changes. However, when I start the X server, but
switch back to the console with CTRL-ALT-F1, there are no skips.

Apparently, some Ubuntu users experienced the same problem:

http://ubuntuforums.org/archive/index.php/t-17816.html
https://bugzilla.ubuntu.com/show_bug.cgi?id=7121

I already recompiled the kernel with CONFIG_PREEMPT, but that doesn't
help. Is this some timing issue in the X server (X.org 6.8.2)? Is
there something else to try?

--
Dick Streefland //// Altium BV
dick.streefland@xxxxxxxxx (@ @) http://www.altium.com
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