regression - suspend to mem stops working somewhere between 5.4.0-29.33 and 5.4.0-66.74

[David Monro]

I have one system where I use rtcwake in a cron job to have it sleep and wake up at certain times of day. I upgraded from linux-image-5.4.0-29-generic (5.4.0-29.33) to linux-image-5.4.0-66-generic (5.4.0-66.74) and the rtcwake command no longer works, failing with 'write error'.

From dmesg, the reason for this is the inability to suspend a usb device:

[240303.355471] PM: dpm_run_callback(): usb_dev_suspend+0x0/0x20 returns -16
[240303.355475] PM: Device usb4 failed to suspend async: error -16

usb4 appears to be the xhci controller?
# ls -l /sys/bus/usb/devices/usb4
lrwxrwxrwx 1 root root 0 Mar 1 09:36 /sys/bus/usb/devices/usb4 -> ../../../devices/pci0000:00/0000:00:14.0/usb4

# lspci -s 00:14.0
00:14.0 USB controller: Intel Corporation 9 Series Chipset Family USB xHCI Controller

System is an older ASRock H97M-ITX/ac board. It does have a quirk which may be relevant - it reports what I think is every port as having an over-current condition on boot:

# dmesg |grep over-current
[ 1.083073] usb 1-1-port3: over-current condition
[ 1.115054] usb 2-1-port5: over-current condition
[ 1.138911] usb usb3-port7: over-current condition
[ 1.299066] usb 1-1-port4: over-current condition
[ 1.331053] usb 2-1-port6: over-current condition
[ 1.354886] usb usb3-port8: over-current condition
[ 1.570911] usb usb3-port9: over-current condition
[ 1.786908] usb usb3-port10: over-current condition

This occurs even when _no_ usb devices (or even internal cables!) are plugged into it (including removing the internal wifi/bluetooth card). It occurs on both the older (working) and newer (failing) kernel.

Based on a couple of random internet posts I tried adding usbcore.autosuspend=-1 and hpet=disable to the kernel command line, but neither seemed to have any impact.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-5.4.0-66-generic 5.4.0-66.74
ProcVersionSignature: Ubuntu 5.4.0-66.74-generic 5.4.86
Uname: Linux 5.4.0-66-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k5.4.0-66-generic.
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/controlC1', '/dev/snd/hwC1D0', '/dev/snd/pcmC1D2c', '/dev/snd/pcmC1D1p', '/dev/snd/pcmC1D0c', '/dev/snd/pcmC1D0p', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D10p', '/dev/snd/pcmC0D9p', '/dev/snd/pcmC0D8p', '/dev/snd/pcmC0D7p', '/dev/snd/pcmC0D3p', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer'
Card1.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
Card1.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer'
CasperMD5CheckResult: pass
Date: Mon Mar 1 10:26:21 2021
InstallationDate: Installed on 2020-05-03 (301 days ago)
InstallationMedia: Ubuntu-Server 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-66-generic root=UUID=f003a362-dec7-4b1d-8208-e30812b865bc ro
RelatedPackageVersions:
 linux-restricted-modules-5.4.0-66-generic N/A
 linux-backports-modules-5.4.0-66-generic N/A
 linux-firmware 1.187.9
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/13/2016
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P1.90
dmi.board.name: H97M-ITX/ac
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP1.90:bd06/13/2016:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnH97M-ITX/ac:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To Be Filled By O.E.M.
dmi.product.name: To Be Filled By O.E.M.
dmi.product.sku: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.

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

This change was made by a bot.