CPU can't reach full speed after resuming from sleep

[Luis Alberto Pabón]

This happens very sporadically after upgrading to 20.04 (not an issue before focal).

Sometimes, after resuming from sleep, the CPU won't go over 1.23GHz. It will scale up and down between this and the min speed (800MHz) but go no higher. Putting the laptop to sleep and resuming brings it back to normal.

I can't find a reliable way of reproducing it as it seems to happen at random.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-generic 5.4.0.40.43
ProcVersionSignature: Ubuntu 5.4.0-40.44-generic 5.4.44
Uname: Linux 5.4.0-40-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: luis 1013521 F.... pulseaudio
CasperMD5CheckResult: skip
CurrentDesktop: sway
Date: Mon Jul 13 09:27:33 2020
InstallationDate: Installed on 2019-08-17 (330 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 04f3:24a0 Elan Microelectronics Corp. Touchscreen
 Bus 001 Device 002: ID 0cf3:e300 Qualcomm Atheros Communications
 Bus 001 Device 004: ID 1bcf:2b95 Sunplus Innovation Technology Inc. Integrated_Webcam_HD
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: Dell Inc. XPS 15 9560
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-40-generic root=/dev/mapper/vglinux-root ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-5.4.0-40-generic N/A
 linux-backports-modules-5.4.0-40-generic N/A
 linux-firmware 1.187.1
SourcePackage: linux
UpgradeStatus: Upgraded to focal on 2020-03-31 (103 days ago)
dmi.bios.date: 05/22/2020
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.19.2
dmi.board.name: 05FFDN
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.19.2:bd05/22/2020:svnDellInc.:pnXPS159560:pvr:rvnDellInc.:rn05FFDN:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 15 9560
dmi.product.sku: 07BE
dmi.sys.vendor: Dell Inc.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Luis Alberto Pabón (copong)]

Dmesg above has such a faulty resume. Laptop went to sleep `Jul 12 19:56:05` and awoke to a faulty cpu state at `Jul 13 09:17:14`