Display corruption during boot process

[Chris Roberts]

ThinkPad X1 Carbon Gen3.

With the 3.19.0-25 kernel included in the 14.04-3 ISO download all works perfectly.

The first software updates include 3.19.0-30 kernel which exhibits the issue:

Display pauses at Drive Encryption password, but you cannot see anything beyond a white screen with uneven black vertical lines. Typing the drive encryption password seems to affect this corrupted screen and then hitting enter results in the the boot process continuing.

Once it reaches lightdm all is well.

Installing mainline kernel 3.19.8-031908ckt7 still suffers from display corruption - block characters instead of text for example - but a new Drive Encryption password prompt appears which works fine.

Uncertain if this is an i915 bug or a plymouth bug or both. I note that there were a number of i915 changes between 3.19.0-25 and 3.19.0-30.

See screen photograph attachment.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: plymouth 0.8.8-0ubuntu17.1
ProcVersionSignature: Ubuntu 3.19.0-30.34~14.04.1-generic 3.19.8-ckt6
Uname: Linux 3.19.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.15
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Oct 7 15:33:07 2015
DefaultPlymouth: /lib/plymouth/themes/ubuntu-logo/ubuntu-logo.plymouth
InstallationDate: Installed on 2015-10-05 (2 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
MachineType: LENOVO 20BS006EUK
ProcCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-30-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash elevator=noop vt.handoff=7
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-30-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash elevator=noop vt.handoff=7
SourcePackage: plymouth
TextPlymouth: /lib/plymouth/themes/ubuntu-text/ubuntu-text.plymouth
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/12/2015
dmi.bios.vendor: LENOVO
dmi.bios.version: N14ET28W (1.06 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20BS006EUK
dmi.board.vendor: LENOVO
dmi.board.version: SDK0E50510 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN14ET28W(1.06):bd03/12/2015:svnLENOVO:pn20BS006EUK:pvrThinkPadX1Carbon3rd:rvnLENOVO:rn20BS006EUK:rvrSDK0E50510WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.name: 20BS006EUK
dmi.product.version: ThinkPad X1 Carbon 3rd
dmi.sys.vendor: LENOVO

[Chris Roberts (chrisjrob)]

Output from lshw attached.

[Steve Langasek (vorlon)]

On Wed, Oct 07, 2015 at 02:44:27PM -0000, Chris Roberts wrote:
> ThinkPad X1 Carbon Gen3.

> With the 3.19.0-25 kernel included in the 14.04-3 ISO download all works
> perfectly.

> The first software updates include 3.19.0-30 kernel which exhibits the
> issue:

It at least seems possible that this issue is related to kernel bug
#1503417. You may want to follow along with the debugging happening there.

[Chris Roberts (chrisjrob)]

Yes sounds possible. I didn't have much luck disabling splash - it resolved the white screen with black lines, but the text was usually just corrupt blocks.