VIA C3 (Ezra C5C) Crashes with longhaul Freq scaling

From: Shinichi Kudo
Date: Sat Mar 04 2006 - 09:48:56 EST

After compiling my own kernels from 2.6.11 to 2.6.14, I found that
only the Ubuntu official kernel didn't lock up hard after 2 hours or
so. Why? Because it didn't provide the frequency scaling driver
longhaul.ko for my VIA C3 CPU. WIthout longhaul frequency scaling, my
laptop is rock stable.

According to , this has been going on since kernel 2.4!

In Dave Jones says,
Version 2 of longhaul is the same as v1, but adds voltage scaling.
12 * Present in Samuel 2 (steppings 1-7 only) (C5B), and Ezra (C5C)

Output of cat /proc/cpuinfo included.
Output of dmesg also included.

As you can see, dmesg says the kernel detected a Ezra C5C version of
VIA C3. However, it also goes on to say, only longhaul v1 supported.
What's with that? Does that have anything to do with the laptop

When the laptop locks, nothing on the screen moves. I can adjust
screen brightness even in the bios, but once it locks, I cannot do
that. Numlock,Capslock,Scrolllock do not change when I press their
buttons either, and pinging my lockedup laptop does not solicit a

So, it is unfortunate, but I don't think any kernel dumps or panic
messages were output. I should know. I've been experiencing this for a
year or so.

Please, somebody fix this frequency scaling issue!

AMD Throughbred-A 1533MHz, 768MB PC2100 RAM, Maxtor 6EL040,
NV25 Ti4200 128MB

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