7

The fault:

ACPI: Video Device [VGA1] (multi-head: yes  rom: no  post: no)
ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.GP17.VGA.LCD._BCM.AFN7], AE_NOT_FOUND (20190816/psargs-330)
Initialized Local Variables for Method [_BCM]:
Local0: 00000000ea353c08 <Obj>           Integer 00000000000000FF
Local1: 00000000418bc901 <Obj>           Integer 0000000000000000
Initialized Arguments for Method [_BCM]:  (1 arguments defined for method invocation)
Arg0:   00000000c180e4bd <Obj>           Integer 0000000000000064
ACPI Error: Aborting method \_SB.PCI0.GP17.VGA.LCD._BCM due to previous error (AE_NOT_FOUND) (20190816/psparse-531)
ACPI Error: Evaluating _BCM failed (20190816/video-357)

My System: ASRock B450 PRO4 Mainboard, AMD Ryzen 3 2200G, Ubuntu 18.04, Kernel 5.4.0-45-generic, amdgpu is loaded... Perhaps someone can help please.

lshw -c video
  *-display                 
       description: VGA compatible controller
       product: Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series]
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:09:00.0
       version: c8
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi msix vga_controller bus_master cap_list rom
       configuration: driver=amdgpu latency=0
       resources: irq:63 memory:c0000000-cfffffff memory:d0000000-d01fffff ioport:f000(size=256) memory:fce00000-fce7ffff memory:c0000-dffff
guiverc
  • 30,396
Christian Völkel
  • 71

3 Answers3

6

The ACPI driver attempted to evaluate (execute) the ACPI brightness control method for the screen but this failed because the ACPI AML byte code in your firmware did not have the object _SB.PCI0.GP17.VGA.LCD._BCM.AFN7 defined for some reason. The upshot of all of this is that the ACPI brightness control won't work. This is a firmware issue, I do not know of any workarounds apart from checking to see if you can get an updated BIOS firmware that may fix this.

Colin Ian King
  • 18,820
3

I have a different mainboard but a very similar error message:

ACPI: \_SB_.PCI0.GP17.VGA_.LCD_: _BCM evaluation failed

My conclusion and fix: The ACPI backlight driver does not work with my mainboard, this seems to be a firmware issue. But you can pass different options to the kernel parameter acpi_backlight. In my case I choose

acpi_backlight=vendor

to enable a vendor specific driver (which I do not use though). The error message is gone. This wiki has some good hints as well.

smartmic
  • 131
  • 3
  • Hi for completeness, could you add how/where you passed the parameter to the kernel? – Hastur Oct 17 '22 at 08:41
  • 1
    @Hastur I am not running Ubuntu but Void Linux. There, I append the kernel parameter (now: acpi_backlight=none) to the GRUB_CMDLINE_LINUX_DEFAULT option in /etc/default/grub and regenerate the initramfs. The same should work for Ubuntu as well, check here – smartmic Oct 17 '22 at 15:17
2

BIOS

ASRock B450 PRO4

You have BIOS version 4.20.

ASRock does NOT recommend updating to this BIOS if Pinnacle, Raven or Summit Ridge CPU is being used on your system.

There's an older BIOS available, version 3.50, dated 7/25/2019, (see note below), and it can be downloaded here.

Note: Confirm that I have the correct web page for your motherboard.

Note: Take note of the warnings about some CPUs and BIOS updates. You have AMD Ryzen 3 2200G (Raven Ridge). See the CPU Support page.

Note: Have good backups before updating the BIOS.

heynnema
  • 70,711
  • I have already the newest BIOS Version P4.20 installed... So should I go back to Version 3.50 ??? – Christian Völkel Sep 03 '20 at 13:45
  • sudo dmidecode -s bios-version P4.20 – Christian Völkel Sep 03 '20 at 13:57
  • @ChristianVölkel I'd recommend talking with the ASRock Support folks, and ask them why newer versions of the BIOS aren't recommended for Raven processors. Then you'll know what to do. Report back. – heynnema Sep 03 '20 at 20:14
  • @ChristianVölkel Status please... – heynnema Sep 08 '20 at 13:53
  • I have almost the same MB B450M and I have same issue. with latest update of BIOS 4.60 and Kubuntu 22.04 with kernel x86_64 Linux 5.15.0-58-generic upgraded from Kubuntu 20.04 that initially had been installed on an old Toshiba Satellite laptop then I moved the HDD to my new desktop. – SaidbakR Feb 04 '23 at 13:54