Bug 150893 (IT_71107)

Summary: On few Nocona based platforms, acpi-cpufreq driver assumes the wrong CPU freq at boot time
Product: Red Hat Enterprise Linux 4 Reporter: Venkatesh Pallipadi <venkatesh.pallipadi>
Component: kernelAssignee: Geoff Gustafson <grgustaf>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.0CC: davej, riel, tao
Target Milestone: ---   
Target Release: ---   
Hardware: i686   
OS: Linux   
Whiteboard:
Fixed In Version: RHSA-2006-0132 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-03-07 18:47:07 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 168429    
Attachments:
Description Flags
Patch
none
Updated patch none

Description Venkatesh Pallipadi 2005-03-11 19:07:42 UTC 
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)

Description of problem:

This bug was uncovered on a Nocona based platform, that supports Enhanced 
Speedstep (EST), has 3 possible frequencies (3.6, 3.2 and 2.8 GHz). But, at 
the boot time system comes up with 2.8 GHz. In this case, acpi-cpufreq wrongly 
assumes that CPU is running at maximum (3.6 GHz) speed. And when there are no 
cpufreq governors running (either userspace or ondemand), the CPUs keep 
running at the lowest freq, while OS reports that it is running at the highest 
freq.

Attached patch fixes the issue. A similar patch has also been sent to upstream 
base kernel.


Version-Release number of selected component (if applicable):
2.6.9-5

How reproducible:
Always

Steps to Reproduce:
1. Enable GV3 in BIOS
2. Disable cpufreq daemon
3. Reboot the system


  

Actual Results:  On this particular system, it is running at 2.8 GHz, but kernel reports 3.6 under sysfs

Expected Results:  Kernel should report 2.8 GHz

Additional info:
Comment 1 Venkatesh Pallipadi 2005-03-11 19:09:15 UTC 
Created attachment 111901 [details]
Patch

This bug is there in both i386 and x86-64 kernels. 
Attached patch fixes the bug in both kernels.
Comment 5 Geoff Gustafson 2005-06-24 15:39:51 UTC 
Created attachment 115937 [details]
Updated patch

The wrong version of the patch was posted, this one is correct.
Comment 8 Geoff Gustafson 2005-10-11 21:01:17 UTC 
I will reverify with the latest code and post it for inclusion in U3.
Comment 16 Red Hat Bugzilla 2006-03-07 18:47:07 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2006-0132.html