Public bug reported:
Please add kernel boot quirks/workarounds for Lenovo LOQ 15ARP9 (Model
83JC, BIOS PQCN31WW).
The broken vendor BIOS firmware causes critical usability issues out of
the box:
1. Backlight brightness control fails completely on GPU/ACPI interface:
[dmesg] nouveau 0000:01:00.0: drm: [DRM/0000000b:kmsOutp] [BL_GET level:0]
(ret:-22)
[dmesg] ACPI: \_SB_.PCI0.GPP0.PEGP.LCD0: _BCM evaluation failed
2. Touchpad stutters and fails to register inputs properly due to invalid I2C
reports:
[dmesg] i2c_hid_acpi i2c-FTCS0038:00: i2c_hid_get_input: incomplete report
(32/66)
3. Duplicate ACPI objects in vendor tables breaking audio/ACP initialization:
[dmesg] ACPI BIOS Error (bug): Failure creating named object
[\_SB.PCI0.GP17.ACP._WOV], AE_ALREADY_EXISTS
System Specs:
- Manufacturer: LENOVO
- Family/Model: LOQ 15ARP9 (83JC)
- BIOS Version: PQCN31WW (Release Date: 07/09/2026)
Ubuntu 7.0.0-34.34~24.04.1-generic 7.0.14
This renders basic laptop usability impossible (display stuck at full
brightness, touchpad dropping inputs). Please apply DMI-matching quirks
for LOQ 15ARP9 in the next kernel HWE update as soon as possible.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Attachment added: "lspci-vnvn.log"
https://bugs.launchpad.net/bugs/2169034/+attachment/6003877/+files/lspci-vnvn.log
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https://bugs.launchpad.net/bugs/2169034
Title:
CRITICAL: Lenovo LOQ 15ARP9 (83JC) broken BIOS ACPI tables, backlight
and I2C touchpad fail
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