Bug 4833 - ACPI: C2 no longer detected for CPU
Summary: ACPI: C2 no longer detected for CPU
Status: CLOSED CODE_FIX
Alias: None
Product: Alternate Trees
Classification: Unclassified
Component: mm (show other bugs)
Hardware: i386 Linux
: P2 normal
Assignee: Andrew Morton
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2005-07-02 07:26 UTC by Jindrich Makovicka
Modified: 2005-07-12 03:23 UTC (History)
0 users

See Also:
Kernel Version: 2.6.13-rc1-mm1
Subsystem:
Regression: ---
Bisected commit-id:

Attachments
.config (40.55 KB, text/plain)
2005-07-02 07:28 UTC, Jindrich Makovicka 		Details
fix (436 bytes, patch)
2005-07-02 09:25 UTC, Jindrich Makovicka 		Details | Diff
Add an attachment (proposed patch, testcase, etc.)

Description Jindrich Makovicka 2005-07-02 07:26:57 UTC 
Distribution: Debian Sid
Hardware Environment: Athlon XP-M 2600+, EPoX 8K9A3+ (VIA KT400)
Problem Description:

With 2.6.13-rc1-mm1, ACPI does no longer detect C2 power state for CPU, only C1,
leaving CPU running full throttle all the time. 2.6.12-mm2 still uses C2.

Steps to reproduce: happens always on my machine. config attached.
Comment 1 Jindrich Makovicka 2005-07-02 07:28:08 UTC 
Created attachment 5250 [details]
.config
Comment 2 Jindrich Makovicka 2005-07-02 09:25:38 UTC 
Created attachment 5251 [details]
fix

this patch adds a call to acpi_processor_power_verify(), which can set .valid
field if appropriate, enabling C2/C3 power state(s).
Comment 3 Andrew Morton 2005-07-06 01:10:18 UTC 
Please email me the patch, as described in

http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt
Comment 4 Adrian Bunk 2005-07-12 03:23:22 UTC 
The patch from this bug is already included in 2.6.13-rc2-mm2.
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