*** This bug is a duplicate of bug 1821820 ***
    https://bugs.launchpad.net/bugs/1821820

Here are the relevant portions of my dmesg with drm.debug=14 as a boot
paramater.  You can see my laptops display panel is still failing link
training.

21:00:11 kernel: [drm:intel_dp_get_link_train_fallback_values [i915]] Retrying 
Link training for eDP with same parameters
21:00:11 kernel: [drm:intel_dp_start_link_train [i915]] [CONNECTOR:85:eDP-1] 
Link Training failed at link rate = 324000, lane count = 1
21:00:11 kernel: [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis 
level 0
21:00:11 kernel: [drm:intel_dp_program_link_training_pattern [i915]] Using DP 
training pattern TPS1
21:00:11 kernel: [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis 
level 0
21:00:11 kernel: [drm:intel_dp_start_link_train [i915]] Using LINK_RATE_SET 
value 04


** Attachment added: "dmesg with drm.debug=14"
   
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1824216/+attachment/5255576/+files/log%20messages

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https://bugs.launchpad.net/bugs/1824216

Title:
  Linux 5.0 regression i915 module, black screen on boot for certain
  laptop panels

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  On my Dell XPS 9575, I get a black screen on boot when running the
  19.04 live image, OR after updating from 18.10 to 19.04.  It appears
  to be a kernel related bug that was introduced in 5.0 that is affected
  by certain laptop panels not conforming to their stated
  specifications.

  Several other Dell systems exhibit the same issue, and it's very
  possible that there are other panels used on other systems that will
  also have the same issues.

  Intel is aware of this issue and has already created a patch.  You can
  see the relevant threads here:

  https://bugs.freedesktop.org/show_bug.cgi?id=109959

  And the patch here:

  https://patchwork.freedesktop.org/patch/296411/

  It would be fantastic to get this patch applied before release, as it
  would be very difficult install 19.04 on the affected systems
  otherwise.  I was able to get the live image booted by adding the
  nomodeset kernel parameter to grub, so as a work around you can use
  this approach to install.

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