I had the same Problem with the CPU in my Lenovo T470s. Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz
i tried intel_pstate=disable which did fix the stuck @ 800 MHz Problem. But Managing CPU govenors ans frequencies was still kind of broken with Kernel 5.3.0-40. So I deleted the intel_pstate kernel Parameter and checked the BIOS / EFI for the CPU management settings. After I disabled Intel Speed Stepping in the Bios, everything was working as expected in Linux. intel_pstate is still availible for the Kernel and the Management of Govenors and Frequencies is just working fine. After a bit of reading up un intel_pstate i think I found another possible Solution or the core reason for This Problem. I did not try it since my problem was solved via the Bios Setting, but it reads promissing: https://www.kernel.org/doc/html/v5.3/admin-guide/pm/intel_pstate.html --- snip If the processor supports the HWP feature, it will be enabled during the processor initialization and cannot be disabled after that. It is possible to avoid enabling it by passing the intel_pstate=no_hwp argument to the kernel in the command line. If the HWP feature has been enabled, intel_pstate relies on the processor to select P-states by itself, but still it can give hints to the processor's internal P-state selection logic. What those hints are depends on which P-state selection algorithm has been applied to the given policy (or to the CPU it corresponds to). ---snap -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1838141 Title: intel_pstate not working. CPU frequency fixed at 800MHz. No cpu frequency scaling. Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Confirmed Bug description: intel_pstate not working. CPU frequency fixed at 800MHz. I've tried to modify frequency using "cpufreq-set" and also by directly writing to files in "/sys/devices/system/cpu/cpu0/cpufreq/*" to no success. I tried different versions of kernel, it started working on 4.17.0 but stopped working soon. These are the versions I tested. 5.2.3 - Not Working 5.1.0 - Not Working 4.19.60 - Not Working 4.18.20 - Not Working 4.17.19 - Not Working 4.17.10 - Not Working 4.17.5 - Not Working 4.17.3 - Not Working 4.17.2 - Working 4.17.1 - Working 4.17.0 - Working 4.16.18 - Not Working 4.15.0 - Not Working Please let me know if anything else is needed. thanks ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-55-generic 4.15.0-55.60 ProcVersionSignature: Ubuntu 4.15.0-55.60-generic 4.15.18 Uname: Linux 4.15.0-55-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: srijan 2219 F.... pulseaudio CurrentDesktop: KDE Date: Sat Jul 27 11:34:10 2019 InstallationDate: Installed on 2018-11-25 (243 days ago) InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725) Lsusb: Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 0bda:5621 Realtek Semiconductor Corp. Bus 001 Device 002: ID 046d:c534 Logitech, Inc. Unifying Receiver Bus 001 Device 004: ID 8087:0aaa Intel Corp. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Acer Predator PH315-51 ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-55-generic root=UUID=a76bd009-8058-4e96-a8b5-a82b7fbe1ede ro acpi_backlight=vendor i915.modeset=1 i915.enable_guc=3 i915.enable_dc=2 i915.enable_fbc=1 nvme_core.default_ps_max_latency_us=18000000 pcie_aspm=force i915.enable_psr=2 i915.disable_power_well=1 nmi_watchdog=0 RelatedPackageVersions: linux-restricted-modules-4.15.0-55-generic N/A linux-backports-modules-4.15.0-55-generic N/A linux-firmware 1.173.10 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) WifiSyslog: dmi.bios.date: 12/05/2018 dmi.bios.vendor: Insyde Corp. dmi.bios.version: V1.24 dmi.board.asset.tag: Type2 - Board Serial Number dmi.board.name: Sienta_CFS dmi.board.vendor: CFL dmi.board.version: V1.24 dmi.chassis.type: 10 dmi.chassis.vendor: Acer dmi.chassis.version: V1.24 dmi.modalias: dmi:bvnInsydeCorp.:bvrV1.24:bd12/05/2018:svnAcer:pnPredatorPH315-51:pvrV1.24:rvnCFL:rnSienta_CFS:rvrV1.24:cvnAcer:ct10:cvrV1.24: dmi.product.family: Predator Helios 300 dmi.product.name: Predator PH315-51 dmi.product.version: V1.24 dmi.sys.vendor: Acer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1838141/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp