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Xenialpup 7.5 32&64 bit cpu frequency scaling not working

Posted: Wed 07 Feb 2018, 21:01
by Ledster
HP 15bs162sa laptop, Intel i5-8250U quad core, 4 Gb ddr4 memory, 1Tb hard disk, UEFI, Intel radio chip 3168NGW (AC3168).
Running xenialpup 7.5 32 or 64 bit cpu frequency scaling does not work. Both Hardinfo and frequency scaling prog show the processor running at 3.4 GHz (its rated frequency is 1.6GHz (3.4GHz in turbo mode).
Any changes I make in the cpu frequency prog are ignored and if I open the prog again the settings have gone back to the default.
Tried tahrpup 6.0.6 and frequency scalling works fine.
FWIW xenialpup says the scaling driver is 'intel_pstate' and 'performance', while tahrpup says 'acpi_cpufreq' and 'ondemand'.
Tried the remove button and a restart - no change. It did not remove.
I do not like the cpu running flat out all the time, seems to run hotter and use the battery faster.
Looks like the driver needs changing, but how and what to?
note - all pups are being run from usb sticks (is it possible to set up more than one pup on a usb stick?).

Hope someone can help.
Cheers
Ledster

Re: Xenialpup 7.5 32&64 bit cpu frequency scaling not working

Posted: Wed 07 Feb 2018, 21:33
by Marv
Ledster wrote:HP 15bs162sa laptop, Intel i5-8250U quad core, 4 Gb ddr4 memory, 1Tb hard disk, UEFI, Intel radio chip 3168NGW (AC3168).
Running xenialpup 7.5 32 or 64 bit cpu frequency scaling does not work. Both Hardinfo and frequency scaling prog show the processor running at 3.4 GHz (its rated frequency is 1.6GHz (3.4GHz in turbo mode).
Any changes I make in the cpu frequency prog are ignored and if I open the prog again the settings have gone back to the default.
Tried tahrpup 6.0.6 and frequency scalling works fine.
FWIW xenialpup says the scaling driver is 'intel_pstate' and 'performance', while tahrpup says 'acpi_cpufreq' and 'ondemand'.
Tried the remove button and a restart - no change. It did not remove.
I do not like the cpu running flat out all the time, seems to run hotter and use the battery faster.
Looks like the driver needs changing, but how and what to?
note - all pups are being run from usb sticks (is it possible to set up more than one pup on a usb stick?).

Hope someone can help.
Cheers
Ledster
Pass

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intel_pstate=disable
as a kernel parameter. Then on your next and subsequent boots wcpufreq should work as normal. So long as the intel driver is enabled in the kernel on intel hardware it will take precedence over the other (acpi_cpufreq etc.) drivers and governors. The tahrpup kernel doesn't have it enabled while the xenialpup kernel must going from your info above. If you are using syslinux on the USB sticks, the kernel parameter can be passed in syslinux.cfg. I only do USB boots to rescue now so I just have one pup on a stick but I have had good success using Grub4Dos for multiple pups on USB hdds and sticks in the past.

Edit: Compiling the kernel with

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#CONFIG_X86_INTEL_PSTATE is not set
eliminates this snafu. (=n may work, having it commented out is more usual) As perhaps you can tell, I'm no fan :lol: of the Intel pstate governor.

Posted: Thu 08 Feb 2018, 13:51
by Ledster
@Marv
Thanks for your answer.
I have never compiled a kernel so wouldn't know how to proceed.
How do I pass your suggestion as a kernel parameter?
I don't know if I am using syslinux or not, but it is on the usb stick. Does this mean it is being used? It was put there when I used the "UEFI installer - Flash Drives" option.

Posted: Thu 08 Feb 2018, 14:17
by Marv
No need for compiling your own kernel. Assuming you are using syslinux, you should find syslinux.cfg on the USB drive. Open it with a text editor such as geany and add intel_pstate=disable (space delimited) to the string you see. For example the contents of my syslinux.cfg are

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default vmlinuz  initrd=initrd.gz intel_pstate=disable pmedia=usbflash pfix=copy
By design, I have no UEFI hardware so don't really know exactly what the installer does in that case. Sorry.

Posted: Thu 08 Feb 2018, 15:59
by Ledster
Sorry about this - I must have been looking at the wrong usb stick! No syslinux on the right one.
However, good news. Looking around found a file in /boot called "config-4.9.58".
Opened this, searched for intel_pstate and found "config_x86_intel_pstate=y" (on line 680 of several thousand!). Hashed this out. and rebooted. Driver is now "acpi-cpufreq" and working fine.

Edit: don't know if it matters, but I had already put "intel_pstate=disable" in grubcfg on the vmlinuz line. It did not work on its own but may be required.

Thanks for the help
Ledster

Posted: Thu 08 Feb 2018, 17:04
by bigpup
entered in error

"intel_pstate=disable"

Posted: Wed 21 Feb 2018, 11:18
by oldprinter
Marv and Ledster -

The "intel_pstate=disable" in grubcfg on the vmlinuz line, works like a charm.

I've tried it in Tahr 6.0.5 and in Xenialpup64 7.5, both booting on a uefi boot (with secureBoot off) machine, Also works on my legacy machines, after adding it to syslinux.cfg.

Many, many thanks for this.

Tom