Bug 10982
| Summary: | scaling_max_freq locked - regression 2.6.18 worked, 2.6.25 fails - Thinkpad T42 | ||
|---|---|---|---|
| Product: | ACPI | Reporter: | Nicolas Vinot (nicolas.vinot) |
| Component: | Power-Processor | Assignee: | Venkatesh Pallipadi (venki) |
| Status: | REJECTED UNREPRODUCIBLE | ||
| Severity: | normal | CC: | acpi-bugzilla, akpm, auke-jan.h.kok, trenn, yakui.zhao |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 2.6.25 | Subsystem: | |
| Regression: | Yes | Bisected commit-id: | |
| Attachments: |
dmesg output
acpidump output |
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Description
Nicolas Vinot
2008-06-25 14:22:51 UTC
Please boot with processor.ignore_ppc=1 or # echo 1 > /sys/module/processor/parameters/ignore_ppc and report if scaling_max_freq stops changing. I marked this as a regression. The T61 where this has been reported recently on the cpufreq list did always show a _PPC value of 0 which is correct. If ignore_ppc=1 still helps it could also be some more complex kernel/cpufreq and not a BIOS/_PPC problem.
Can you reproduce this easily (e.g. always after some short time or trigger it)? The report on the T61 was that it only happens on some boots, which makes it very hard to debug it there or to verify whether a patch/change helps or not.
If this is ACPI thermal related and is a regression it might be this one:
commit d9460fd227ed2ce52941b6a12ad4de05c195f6aa
Date: Thu Jan 17 15:51:23 2008 +0800
ACPI: register ACPI Processor as generic thermal cooling device
If you can reproduce the problem easily, uou may want to give it a try and test with and without that patch (go back the git history if it doesn't patch anymore). git-bisect is also an option then (if easy to reproduce) if it is something else.
With ignore_ppc=1, no problem at all since my last boot. But this problem occures very randomly and in very differente cases (with hot or cold cpu, on heavy load or not, at the launch of screensaver...). So, not sure for the moment the problem is completely resolved with ignore_ppc=1, but in good way. since it (seems) PPC related, moving to ACPI category... re: comment #3, good idea Thomas. Nicolas, does the problem also go away with CONFIG_ACPI_THERMAL=n? re: regression i guess, so since it was not a problem in 2.6.18 and fails in 2.6.25. Nicolas, Assuming the thermal issue isn't it, can you narrow down which release this broken in? No problem today too. It seems to be PPC. For CONFIG_ACPI_THERMAL, my current kernel option is set to "yes". I try tomorrow with "no". For the revision broken, no problem with kernel 2.6.18 and 2.6.21. I don't try with 22 and 24. But i can try it. Latest news. I reinstalled a 2.6.18 kernel (debian package) to test on it. And after a while, same problem, lock of cpufreq_max.... (ignore_ppc isn't set on boot command line, confirm PPC may be guilty) I try to found my old 2.6.18 kernel config to find difference between current version (debian base) which doesn't work and old version (hand-compiled) which hasn't this problem... I recompile my kernel 2.6.25 with CONFIG_ACPI_THERMAL=n. It doesn't resolve my problem. After a new compilation to reactivate thermal acpi, and booting with processor.ignore_ppc=1, the problem is still here! Even if processor.ignore_ppc=1 resolved the problem 48h ago.... This bug seems to occure very randomly......... Is there any way to verbose-log all switches of cpufreq or acpi events? It could be very usefull to find the cause of this bug. Hi, Nicolas
Will you please attach the output of dmesg and acpidump?
Thanks.
Created attachment 16746 [details]
dmesg output
Created attachment 16747 [details]
acpidump output
Sorry for my late, I was very busy this week. Here is my dmesg and acpidump output. For a T42 it could be that (by Bjoern Steinbrink). It might be something else, something is defintely fishy. But you may want to check for this BIOS option: OK, a stop at thinkwiki[1] later, I know what's happening now. The BIOS has a few settings regarding CPU speed on AC/battery. One is about balancing power and noise. The above throttling does no longer kick in if that option is set to "Maximum Power". Björn [1] http://www.thinkwiki.org/wiki/How_to_make_use_of_Dynamic_Frequency_Scaling#Troubleshooting Hi, Nicolas, does the problem still exist in the latest kernel? does comment #14 answer your question? Hi all. I upgrade to kernel 2.6.26 today. Same problem, always random freezes of cpu max freq. Sometimes cpufreq works good, sometimes it doesn't, and I don't find a way to reproduce the failure surely. For BIOS settings, I tried all possible settings, the problem stays. Hi, Nicolas
Do you mean that the problem still exists even when the "processor.ignore_ppc=1" is added?
When the problem appears, please attach the output of /proc/acpi/thermal_zone/thrm/*
thanks.
How to ignore ppc can be referred what Len said in comment #1. thanks. ping Nicolas. ping timeout :) Sorry for my late. With my v2.6.26, problem is resolved after 1 month usage... No kernel update and no acpi or cpufreq update, but it's seems working correctly now. Cpufreq freeze only on (very) high cpu temp (it's advisabled :)) Very stange bug and very strange resolution. well, the problem can not be reproduced, while we still not fix this issue. Reject it. Nicolas, please re-open it if the problem shows up again. |