No video on laptop display after suspend/resume

[John Lindgren]

Between linux 4.15.0-23 and 4.15.0-24, suspend/resume stopped working correctly. After resume, the laptop panel remains blank with -24 (external monitors resume correctly). Suspend/resume worked correctly with -23.

Ubuntu 18.04 LTS
Lenovo P50 laptop, using nouveau driver
---
ProblemType: Bug
ApportVersion: 2.20.9-0ubuntu7.3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: john 1100 F.... pulseaudio
 /dev/snd/controlC0: john 1100 F.... pulseaudio
DistroRelease: Ubuntu 18.04
HibernationDevice: RESUME=UUID=1114cee9-db59-4a6e-a257-06ed1131a72b
InstallationDate: Installed on 2017-02-01 (586 days ago)
InstallationMedia: Xubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
MachineType: LENOVO 20EN001AUS
Package: linux (not installed)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-23-generic root=UUID=cd371ad3-bcc5-4389-b0b7-910bd49727c5 ro quiet
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-23-generic N/A
 linux-backports-modules-4.15.0-23-generic N/A
 linux-firmware 1.173.1
RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill'
Tags: bionic
Uname: Linux 4.15.0-23-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo vboxusers wireshark
_MarkForUpload: True
dmi.bios.date: 03/28/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: N1EET77W (1.50 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20EN001AUS
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40705 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN1EET77W(1.50):bd03/28/2018:svnLENOVO:pn20EN001AUS:pvrThinkPadP50:rvnLENOVO:rn20EN001AUS:rvrSDK0J40705WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad P50
dmi.product.name: 20EN001AUS
dmi.product.version: ThinkPad P50
dmi.sys.vendor: LENOVO

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

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1791321

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

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[John Lindgren (john-lindgren)]

3cd091a773936c54344a519f7ee1379ccb620bee is the first bad commit
commit 3cd091a773936c54344a519f7ee1379ccb620bee
Author: Rafael J. Wysocki <email address hidden>
Date: Fri Feb 9 22:55:28 2018 +0100

    ACPI / EC: Restore polling during noirq suspend/resume phases

    Commit 662591461c4b (ACPI / EC: Drop EC noirq hooks to fix a
    regression) modified the ACPI EC driver so that it doesn't switch
    over to busy polling mode during noirq stages of system suspend and
    resume in an attempt to fix an issue resulting from that behavior.

    However, that modification introduced a system resume regression on
    Thinkpad X240, so make the EC driver switch over to the polling mode
    during noirq stages of system suspend and resume again, which
    effectively reverts the problematic commit.

    Fixes: 662591461c4b (ACPI / EC: Drop EC noirq hooks to fix a regression)
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=197863
    Reported-by: Markus Demleitner <email address hidden>
    Tested-by: Markus Demleitner <email address hidden>
    Signed-off-by: Rafael J. Wysocki <email address hidden>

[John Lindgren (john-lindgren)]

Forwarded to https://bugzilla.kernel.org/show_bug.cgi?id=201091.

[Joseph Salisbury (jsalisbury)]

I built a test kernel with a revert of commit 3cd091a773936c54344a519f7ee1379ccb620bee. The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1791321

Can you test this kernel and see if it resolves this bug?

Note about installing test kernels:
• If the test kernel is prior to 4.15(Bionic) you need to install the linux-image and linux-image-extra .deb packages.
• If the test kernel is 4.15(Bionic) or newer, you need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

Thanks in advance!

[John Lindgren (john-lindgren)]

Yes, the test kernel you uploaded works fine. Thanks.

I wish I understood more of what was behind that bad commit and the previous ones it referenced, since there appears to have been a series of fixes/reversions already, with each one apparently causing new problems on some other system:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c3a696b6e8f8
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=662591461c4b
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3cd091a77393

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.19 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19-rc4

[Joseph Salisbury (jsalisbury)]

I'll ping upstream for feedback if v4.19-rc4 still exhibits the bug.

[John Lindgren (john-lindgren)]

v4.19-rc4 works, v4.18.8 still has the bug.