The issue has been fix in 6.0.0-1016.16 ** Tags removed: verification-needed-jammy ** Tags added: verification-done-jammy
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-oem-6.0 in Ubuntu. 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: In Progress 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. To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/2017774/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
