Bug#981639: linux-image-amd64: external hdmi screen not usable - blue taint and low resolution

[mdedonno <mdedonno1337@gmail.com>]

Package: linux-image-amd64
Version: 4.19+105+deb10u9
Severity: critical
Justification: breaks the whole system
X-Debbugs-Cc: mdedonno1337@gmail.com

Dear Maintainer,

   * Situation summary

I installed Debian 10, and updated the apt source file to point to bullseye, and made all updates as needed.

When the kernel was updated from 5.9 to 5.10.x, the external HDMI screen
was not usable anymore: the resolution was something like 480p, with a
very strong blue taint.

   * What exactly did you do (or not do) that was effective (or

I restared with the 5.9 kernel from grub and the same situation was still present.

This not-usable-external-screen is already present when typing the LUKS
password; I think this issue is not related to a configuration file
stored on the root filesystem, but somewhere in the /boot partition
(kernel or raminitfs).

I tried to reinstall completely the system in different ways.
First, without formatting the /boot partition, but only making a
reinstallation of the system.
The problem was still present.

Then, reinstalling completely the system (debian 10) with a full /boot partition
format, the problem disappears.
An update to Debian 11 makes the issue come back.

   * The current working situation

At the moment, the only solution is to install Debian 10, apt-mark hold
the kernel to the version 4.19, switch the apt source file to bullseye,
and make the installation.


-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-14-amd64 (SMP w/4 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages linux-image-amd64 depends on:
hi  linux-image-4.19.0-14-amd64  4.19.171-2

linux-image-amd64 recommends no packages.

linux-image-amd64 suggests no packages.

-- no debconf information