Bug 59821

Summary:	Dell M4600 CPU cores locked at 800MHz
Product:	Power Management	Reporter:	George B. (list1)
Component:	cpufreq	Assignee:	cpufreq
Status:	CLOSED DOCUMENTED
Severity:	normal	CC:	aaron.lu, tianyu.lan
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	Debian 3.9.4-1 x86_64 GNU/Linux	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	grep . /sys/devices/system/cpu/cpu/cpufreq/ cat /proc/cpuinfo grep . /sys/devices/system/cpu/cpu/cpufreq/ (CONFIG_X86_INTEL_PSTATE) htop screenshot (couln't find a way of getting text out) powertop output

Description George B. 2013-06-17 10:52:41 UTC

Created attachment 104941 [details]
grep . /sys/devices/system/cpu/cpu*/cpufreq/*

Finally opening new bug as requested in bug 42725 comment 81.

When booting my laptop with docking station attached the CPU cores are stuck at 800Mhz.

When booting without the docking station this problem does not appear, but once docking station is attached the cores become locked at 800MHz.

Workaround is to suspend the laptop to RAM (s2ram used) for several seconds and this (almost always) allows CPU cores to scale speed 800 to max 2300000.

Comment 1 George B. 2013-06-17 10:53:57 UTC

Created attachment 104951 [details]
cat /proc/cpuinfo

Comment 2 Lan Tianyu 2013-06-17 12:44:37 UTC

This should be a cpufreq bug and reassign to the correct category. Could you try intel_pstate driver?

Please provide the output of acpidump. Thanks.

Comment 3 George B. 2013-06-17 12:52:24 UTC

(In reply to comment #2)
> Could you try intel_pstate driver?

Not sure how to do this - can you please provide steps?

> Please provide the output of acpidump. Thanks.

root@deli:~ # acpidump
Linux version not implemented yet
Could not get ACPI tables, AE_SUPPORT

Comment 4 Lan Tianyu 2013-06-17 13:09:27 UTC

(In reply to comment #3)
> (In reply to comment #2)
> > Could you try intel_pstate driver?
> Not sure how to do this - can you please provide steps?
Change kernel config file

set CONFIG_X86_INTEL_PSTATE
unset CONFIG_X86_ACPI_CPUFREQ

> > Please provide the output of acpidump. Thanks.
> root@deli:~ # acpidump
> Linux version not implemented yet
> Could not get ACPI tables, AE_SUPPORT
Which kernel version you are using?

Comment 5 George B. 2013-06-17 13:18:38 UTC

root@deli:~ # uname -a
Linux deli 3.9-1-amd64 #1 SMP Debian 3.9.4-1 x86_64 GNU/Linux

Comment 6 George B. 2013-06-17 17:11:13 UTC

Created attachment 105021 [details]
grep . /sys/devices/system/cpu/cpu*/cpufreq/* (CONFIG_X86_INTEL_PSTATE)

Seeing similar behaviour after compiling with CONFIG_X86_INTEL_PSTATE enabled, except when problem occurs CPU speed will go as high as 897000 and when problem cleared with s2ram as high as 3381000.

Also, many more values are seen in between these, whereas with CONFIG_X86_ACPI_CPUFREQ the speed is mostly (maybe even always) either 800000 or 3200000.

Comment 7 Lan Tianyu 2013-06-20 06:48:44 UTC

 Could you provide what powertop and htop show during CPU cores are stuck at
800Mhz.?
(including these powertop's tabs, Overview   Idle stats   Frequency stats,   Device stats, Tunables).

Comment 8 George B. 2013-06-24 09:46:27 UTC

Created attachment 105821 [details]
htop screenshot (couln't find a way of getting text out)

Comment 9 George B. 2013-06-24 09:46:55 UTC

Created attachment 105831 [details]
powertop output

Comment 10 George B. 2013-08-20 13:40:15 UTC

Do you need me to provide any more information? (Bug is still tagged with "NEEDINFO".)

I have now disabled SpeedStep in the BIOS and the problem went away.

Comment 11 Lan Tianyu 2013-10-14 05:14:24 UTC

Sorry for later response. This seems a Bios issue. Is there newer Bios verison.

Comment 12 Lan Tianyu 2013-10-24 07:37:46 UTC

This bug is a Bios issue and can't resolve in the kernel. So close it.