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I have a Lenovo T480s that I connect to my dock at work every day. Today all of a sudden my monitors remain black after I'm prompted for the encryption key for my disk. Usually, the login prompt should turn up.

Booting my machine without the dock works fine. Any ideas to how I can fix this? Any help is appreciated.

Øystein Seel
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1 Answers1

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Did you update the kernel to 4.15.0-44, which was offered yesterday through Ubuntu software update ?

It contains a bug in the graphics driver initialization, which has been reverted into a test kernel 4.15.0-45 available there, which seems to fix the issue for all affected users:

https://people.canonical.com/~khfeng/lp1813663/

Regards

sg2
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    Thanks a lot! Selecting 4.15.0-43 in GRUB also solved the issue for me (on a T440p). – greschd Jan 30 '19 at 09:57
  • Do you have references to know more about this bug? And to follow it's resolution (not yet in 18.04 repositories) – tuxayo Jan 31 '19 at 12:27
  • Here right? https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1813663 – tuxayo Jan 31 '19 at 12:32
  • The bug introduced in -44 is this commit: "drm/i915/dp: Send DPCD ON for MST before phy_up". The test -45 kernel reverts this change. Appearently, the offocial -45 kernel made available today through software update does not contain this revert, since it crashes on boot on my Dell 9370, as -44 does. – sg2 Jan 31 '19 at 15:17