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author | Andreas Herrmann <andreas.herrmann3@amd.com> | 2009-04-22 13:48:33 +0200 |
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committer | Dave Jones <davej@redhat.com> | 2009-05-26 12:04:51 -0400 |
commit | ca446d06351992e4f1a7c1e5e99870ab4ec5188f (patch) | |
tree | fedb65e1059aa04f199d3d306c664674b1217971 /sound | |
parent | df1829770db415dc5a5ed5ada3bd70176c6f0a01 (diff) |
[CPUFREQ] powernow-k8: determine exact CPU frequency for HW Pstates
Slightly modified by trenn@suse.de -> only do this on fam 10h and fam 11h.
Currently powernow-k8 determines CPU frequency from ACPI PSS objects, but
according to AMD family 11h BKDG this frequency is just a rounded value:
"CoreFreq (MHz) = The CPU COF specified by MSRC001_00[6B:64][CpuFid]
rounded to the nearest 100 Mhz."
As a consequnce powernow-k8 reports wrong CPU frequency on some systems,
e.g. on Turion X2 Ultra:
powernow-k8: Found 1 AMD Turion(tm)X2 Ultra DualCore Mobile ZM-82
processors (2 cpu cores) (version 2.20.00)
powernow-k8: 0 : pstate 0 (2200 MHz)
powernow-k8: 1 : pstate 1 (1100 MHz)
powernow-k8: 2 : pstate 2 (600 MHz)
But this is wrong as frequency for Pstate2 is 550 MHz. x86info reports it
correctly:
#x86info -a |grep Pstate
...
Pstate-0: fid=e, did=0, vid=24 (2200MHz)
Pstate-1: fid=e, did=1, vid=30 (1100MHz)
Pstate-2: fid=e, did=2, vid=3c (550MHz) (current)
Solution is to determine the frequency directly from Pstate MSRs instead
of using rounded values from ACPI table.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'sound')
0 files changed, 0 insertions, 0 deletions