Bug#307328: kernel-source-2.6.11: [powerpc] CPU runs only with half speed on new powerbooks
Package: kernel-source-2.6.11
Severity: normal
Hello,
with release 2.6.11-1 of kernel-image-2.6.11-powerpc the CPU runs only
at half of the advertised speed. The problem is hard to notice,
because /proc/cpuinfo contains the lines
cpu : 7447A, altivec supported
clock : 1666MHz
bogomips : 829.44
which look good at first. But is transpires that the clock entry is
wrong! The thing to look out for is the bogomips value: on a 7447A
processor the bogomips value is approximately equal to the clock
frequency.
The issue is discussed in the debian-powerpc mailing list in the thread
starting at http://lists.debian.org/debian-powerpc/2005/03/msg00554.html .
The problem can be fixed with the Benjamin Herrenschmidt's patch from
http://lists.debian.org/debian-powerpc/2005/03/msg00554.html and
http://lists.debian.org/debian-powerpc/2005/03/msg01008.html . A
combined version of these two changes is at
http://seehuhn.de/comp/powerbook/#cpufreq-patch .
Kernel specific information about my machine (/proc/cpuinfo contents
etc.) can be found at http://seehuhn.de/comp/powerbook/2.6.11-1/ ,
general information (about hardware, etc) is at
http://seehuhn.de/comp/powerbook/ .
I hope this helps,
Jochen
-- System Information:
Debian Release: 3.1
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: powerpc (ppc)
Kernel: Linux 2.6.11-powerpc
Locale: LANG=en_GB.iso885915, LC_CTYPE=en_GB.iso885915 (charmap=ISO-8859-15)
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