Bug 8423 - "powernow-k8: Processor cpuid 70ff1 not supported" on Athlon64 3800+ AM2 which supports Cool'n'Quiet
Summary: "powernow-k8: Processor cpuid 70ff1 not supported" on Athlon64 3800+ AM2 whic...
Status: CLOSED CODE_FIX
Alias: None
Product: Power Management
Classification: Unclassified
Component: cpufreq (show other bugs)
Hardware: i386 Linux
: P2 low
Assignee: Mark Langsdorf
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2007-05-03 03:10 UTC by Tomasz Ostrowski
Modified: 2007-05-17 14:11 UTC (History)
0 users

See Also:
Kernel Version: 2.6.21.1
Subsystem:
Regression: ---
Bisected commit-id:


Attachments
x86info output (4.19 KB, text/plain)
2007-05-03 03:13 UTC, Tomasz Ostrowski
Details
Change RevF numbers in powernow-k8 (593 bytes, patch)
2007-05-03 09:32 UTC, Mark Langsdorf
Details | Diff

Description Tomasz Ostrowski 2007-05-03 03:10:48 UTC
Most recent kernel where this bug did *NOT* occur: unknown
Distribution: vanilla kernel copiled with FC6 gcc-4.1.1-51.fc6
Hardware Environment: AMD Athlon64 3800+ AM2 on Gigabyte GA-M61PM-S2, latest BIOS
Software Environment: Fedora Core 6

Problem Description:
Powernow-k8 driver does not load - it shows a message
    powernow-k8: Processor cpuid 70ff1 not supported
on my new AMD Athlon64 3800+ on AM2 connector (Family: 15 Model: 15 Stepping:
1), which does support Cool'n'Quiet. Because of this I cannot use cpufreq in my
system.

I think it triggers a check
    (eax & CPUID_XMOD) > CPUID_XMOD_REV_G)
from row 524 in arch/i386/kernel/cpu/cpufreq/powernow-k8.c.

Macros CPUID_XMOD and CPUID_XMOD_REV_G are defined in
./arch/i386/kernel/cpu/cpufreq/powernow-k8.h:
    #define CPUID_XMOD                      0x000f0000      /* extended model */
    #define CPUID_XMOD_REV_G                0x00060000

Steps to reproduce:
1. compile kernel with powernow-k8 support
2. boot on Athlon64 3800+ AM2
Comment 1 Tomasz Ostrowski 2007-05-03 03:13:41 UTC
Created attachment 11381 [details]
x86info output
Comment 2 Mark Langsdorf 2007-05-03 09:28:58 UTC
Known bug; correcting patch was submitted on February 23, 2007.
Correcting patch attached.
Comment 3 Mark Langsdorf 2007-05-03 09:32:52 UTC
Created attachment 11385 [details]
Change RevF numbers in powernow-k8
Comment 4 Dave Jones 2007-05-13 15:06:52 UTC
not sure what happened to your earlier patch, but I don't seem to be able to
find it.  Someone else mailed me a patch yesterday which fixes the problem for
him, so I merged it and pushed it on to Linus.  That one replaced 

#define CPUID_XMOD_REV_G 0x00060000
with
#define CPUID_XMOD_REV_H 0x00070000

Whilst the patch you attached here bumps it to 80000.  Does RevH span two
revisions?, or were you thinking ahead for RevI :-)
Comment 5 Dave Jones 2007-05-17 14:11:56 UTC
now fixed in Linus tree, and pushed to stable@

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