[flicker free boot] boot image disappears for a second before LUKS prompt

[Luis Alberto Pabón]

The display goes black at some point after BIOS boot and LUKS prompt, where original boot image is restored alongside Ubuntu's boot bits.

Best shown in a video: https://www.youtube.com/watch?v=YUtlE6YkFuk

Dell XPS 9560

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: plymouth 0.9.4git20200323-0ubuntu5
ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27
Uname: Linux 5.4.0-21-generic x86_64
ApportVersion: 2.20.11-0ubuntu24
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CurrentDesktop: Unity
Date: Wed Apr 8 14:17:01 2020
DefaultPlymouth: /usr/share/plymouth/themes/bgrt/bgrt.plymouth
InstallationDate: Installed on 2019-08-17 (234 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
MachineType: Dell Inc. XPS 15 9560
ProcCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-21-generic root=/dev/mapper/vglinux-root ro quiet splash vt.handoff=7
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-21-generic root=/dev/mapper/vglinux-root ro quiet splash vt.handoff=7
SourcePackage: plymouth
TextPlymouth: /usr/share/plymouth/themes/ubuntu-text/ubuntu-text.plymouth
UpgradeStatus: Upgraded to focal on 2020-03-31 (7 days ago)
dmi.bios.date: 11/17/2019
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.18.0
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.:bvr1.18.0:bd11/17/2019: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.

[Luis Alberto Pabón (copong)]

journalctl -b 0

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1836858, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.

[Sebastien Bacher (seb128)]

Daniel, I think there is no evidence there that it's the same problem that the one you duplicated from.

@Luis, could you add "drm.debug=0x4 log_buf_len=10M" to your kernel commandline (https://wiki.ubuntu.com/Kernel/KernelBootParameters) and then after boot do:
dmesg > dmesg.txt
And attach dmesg.txt to the report?

[Daniel van Vugt (vanvugt)]

This is precisely the problem I describe in bug 1836858. Doesn't matter if there's a password prompt or not.

[Daniel van Vugt (vanvugt)]

This is a duplicate of bug 1836858.

[Luis Alberto Pabón (copong)]

Attached dmesg with drm.debug=0x4 log_buf_len=10M boot options

[Sebastien Bacher (seb128)]

Thanks, so that's not the same error than on the XPS 13 I was mentioning on discourse. Could you try to boot using 'plymouth:debug' (https://wiki.ubuntu.com/Kernel/KernelBootParameters) and add the /var/log/plymouth.log ?

[Luis Alberto Pabón (copong)]

plymouth debug log with `quiet splash drm.debug=0x4 log_buf_len=10M plymouth:debug` boot

[Luis Alberto Pabón (copong)]

dmesg with `quiet splash drm.debug=0x4 log_buf_len=10M plymouth:debug` boot

[Luis Alberto Pabón (copong)]

Uploaded the plymouth log and corresponding dmesg above.

There's been a change to the boot process after adding `plymouth:debug`. Now, it briefly (less than 200ms I reckon) shows the boot log before going back to the dell / ubuntu / crypto password prompt stage.

[Launchpad Janitor (janitor)]

[Expired for plymouth (Ubuntu) because there has been no activity for 60 days.]

[Daniel van Vugt (vanvugt)]

I experience this problem on my focal desktop with the LUKS prompt. And I can confirm it's just another duplicate of bug 1836858.

[Luis Alberto Pabón (copong)]

Thank you Daniel, I'll follow the other bug.