This bug was fixed in the package linux-oem-6.0 - 6.0.0-1016.16

---------------
linux-oem-6.0 (6.0.0-1016.16) jammy; urgency=medium

  * jammy/linux-oem-6.0: 6.0.0-1016.16 -proposed tracker (LP: #2016550)

  * both dell_backlight and nvidia_0 backlight interface appear, and can't
    adjust the display  brightness (LP: #2017774)
    - ACPI: video: Add acpi_video_backlight_use_native() helper
    - ACPI: video: Drop backlight_device_get_by_type() call from
      acpi_video_get_backlight_type()
    - ACPI: video: Refactor acpi_video_get_backlight_type() a bit
    - ACPI: video: Make acpi_video_backlight_use_native() always return true
    - ACPI: video: Simplify __acpi_video_get_backlight_type()
    - ACPI: video: Prefer native over vendor

  * CVE-2022-4139
    - drm/i915: fix TLB invalidation for Gen12 video and compute engines

 -- Timo Aaltonen <timo.aalto...@canonical.com>  Thu, 27 Apr 2023
13:15:34 +0300

** Changed in: linux-oem-6.0 (Ubuntu Jammy)
       Status: In Progress => Fix Released

** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2022-4139

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https://bugs.launchpad.net/bugs/2017774

Title:
  both dell_backlight and nvidia_0 backlight interface appear, and can't
  adjust the display  brightness

Status in HWE Next:
  New
Status in linux package in Ubuntu:
  Fix Released
Status in linux-oem-6.0 package in Ubuntu:
  Invalid
Status in linux source package in Jammy:
  Invalid
Status in linux-oem-6.0 source package in Jammy:
  Fix Released

Bug description:
  [Impact]
  When switched to discrete mode in the BIOS, nvidia driver will create its own 
backlight interface(nvidia_0) to control the backlight, but at the same time 
dell-laptop creates its own backlight interface(dell_backlight), too. In 
discrete mode, dell_backlight interface doesn't work, and it leads to gnome 
chooses the wrong interface(dell_backlight) to control the backlight and then 
leads to the issue.

  
  [Fix]
  The acpi_video_backlight_use_native() helper function is introduced after 
v6.1 and nvidia driver will call this function if kernel provides it. This 
helper tells video_detect module that nvidia controls the backlight, so that 
dell-laptop won't create another backlight interface when it's loaded

  Below commits are all from v6.1-rc1
  fb1836c91317 ACPI: video: Prefer native over vendor
  a5df42521f32 ACPI: video: Simplify 
__acpi_video_get_backlight_type()454d61a56d5e ACPI: video: Make 
acpi_video_backlight_use_native() always return true
  b39be9f441f9 ACPI: video: Refactor acpi_video_get_backlight_type() a bit
  a2fc3c899bb0 ACPI: video: Drop backlight_device_get_by_type() call from 
acpi_video_get_backlight_type()
  2600bfa3df99 ACPI: video: Add acpi_video_backlight_use_native() helper

  
  [Test]
  Verified on the target machine and confirmed dell_backlight interface is not 
generated.

  [Where problem could occur]
  All changes are in __acpi_video_get_backlight_type() function and to make it 
smarter to decide which type of backlight interface should be created. The 
final result is pretty similar to the latest mainline version, if it introduce 
any regression we can add quirk to list those misjudged machines.

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