Bug 15295
| Summary: | scaling_max_freq value lost upon suspend | ||
|---|---|---|---|
| Product: | Power Management | Reporter: | Sophia Herzog (sophia_h) |
| Component: | cpufreq | Assignee: | Rafael J. Wysocki (rjw) |
| Status: | CLOSED CODE_FIX | ||
| Severity: | normal | CC: | aaron.lu, alan, rui.zhang, tianyu.lan, wmlongman, z_kvn |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 3.6.7 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
Kernel Configuration
dmesg - Kernel Ring Buffer Output of "grep . /sys/devices/system/cpu/cpu*/cpufreq/*" before suspending Output of "grep . /sys/devices/system/cpu/cpu*/cpufreq/*" after suspending |
||
Created attachment 25038 [details]
dmesg - Kernel Ring Buffer
It's great that kernel bugzilla is back. can you please verify if the problem still exists in the latest upstream kernel? Hello I can confirm this bug persists with below kernal ThinkPad-X220 3.0.0-16-generic #28-Ubuntu SMP Fri Jan 27 17:44:39 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux In my /etc/rc.local I have below script to change scaling_max_freq of four cores for i in 0 1 2 3; do echo 2400000 > /sys/devices/system/cpu/cpu$i/cpufreq/scaling_max_freq; done However after suspend, only CPU0 stays 2400000, all other three changed to maximum of 2401000 please attach the output of "grep . /sys/devices/system/cpu/cpu*/cpufreq/*" both before and after suspend. Created attachment 87471 [details]
Output of "grep . /sys/devices/system/cpu/cpu*/cpufreq/*" before suspending
Created attachment 87481 [details]
Output of "grep . /sys/devices/system/cpu/cpu*/cpufreq/*" after suspending
Last reproduced using Linux 3.6.7 on x86_64 Hi Sophia & z_kvn, I believe the following commit should fix this issue: commit a66b2e503fc79fff6632d02ef5a0ee47c1d2553d Author: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Date: Wed May 15 21:47:17 2013 +0200 cpufreq: Preserve sysfs files across suspend/resume I've tested locally and it works for me, but it would be good if you can give it a test too, v3.10-rc2 above kernels are required, thanks. *** Bug 41292 has been marked as a duplicate of this bug. *** Hi, Please check whether this bug still exists on the v3.10-rc4. If yes, try intel_pstate driver again. Thanks. ... Overlap. Anyway please try newest kernel. Hi Rafael, Should the commit mentioned in comment #8 go into stable tree? On Tuesday, June 18, 2013 03:10:40 AM bugzilla-daemon@bugzilla.kernel.org wrote: > --- Comment #12 from Aaron Lu <aaron.lu@intel.com> 2013-06-18 03:10:40 --- > Hi Rafael, > > Should the commit mentioned in comment #8 go into stable tree? I believe so. I also think that this bug may be closed. I agree. I just want to be sure after user confirmed, but looks like he is not available any more, so I'll close it. |
Created attachment 25037 [details] Kernel Configuration Bug: Altered scaling_max_freq should be preserved over suspend-cycles. Steps to reproduce: 0. Compile and boot kernel according to the attached .config 1. Alter scaling_max_freq 2. Suspend to RAM and wake up 3. scaling_max_freq is set to it's maximum