<html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body> Hello, I'm running into a kernel problem on openSUSE. After investigation and various tests, the openSUSE kernel maintainer determined it's an upstream kernel issue, which I should report upstream. I believe this mailing list should be the correct starting point for my bug report. Please correct me if this is not the case. The original bug report can be found here: <a class="moz-txt-link-freetext" href="https://bugzilla.opensuse.org/show_bug.cgi?id=1186896">https://bugzilla.opensuse.org/show_bug.cgi?id=1186896</a> === Summary=== I don't have brightness control or an external screen, without disabling acpi. If I disable acpi (kernel boot option "acpi=off") than I do have brightness control, and the external screen works too. But obviously I then don't have any acpi functionality (single core, Fn keys, etc) ===Details=== Laptop: Clevo NL51RU BIOS: insyde 1.07.05 Distribution: openSUSE Leap 15.2/15.3 + Tumbleweed Recent kernels tried (from the openSUSE repos): kernel-default-5.12.12 kernel-default-5.13.rc7 CPU: Rhyzen 7 4700U Graphics: # lspci -nnk | grep -A3 VGA 05:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Renoir [1002:1636] (rev c2) Subsystem: CLEVO/KAPOK Computer Device [1558:a500] Detailed symptoms: <table width="1022" height="148" cellspacing="2" cellpadding="2" border="1"> <tbody> <tr> <td valign="top">Boot option </td> <td valign="top">Boots? </td> <td valign="top">Brightness? </td> <td valign="top">Notes </td> </tr> <tr> <td valign="top">- </td> <td valign="top">No </td> <td valign="top"> </td> <td valign="top">Hangs at "switching to amdgpudrmfb from EFI VGA" [*] </td> </tr> <tr> <td valign="top">nomodeset </td> <td valign="top">Yes </td> <td valign="top">No </td> <td valign="top">Any attempt to set the brightness results in the external monitor widget to popup </td> </tr> <tr> <td valign="top">amdgpu.backlight=0 </td> <td valign="top">No </td> <td valign="top"> </td> <td valign="top">Hangs at "switching to amdgpudrmfb from EFI VGA" [*] </td> </tr> <tr> <td valign="top">amdgpu.backlight=0 nomodeset </td> <td valign="top">Yes </td> <td valign="top">No </td> <td valign="top"> </td> </tr> <tr> <td valign="top">acpi=off </td> <td valign="top">Yes </td> <td valign="top">Yes </td> <td valign="top">No acpi functionality </td> </tr> </tbody> </table> For those two scenarios above where the laptop boots fine, but without brightness control, there is this funny additional symptom: Turning the scroll wheel over de battery icon in the system tray doesn't do anything. No change in brightness. But I do get the immediate and unexplainable popup of the external monitor widget (see attachment). Peculiarly, the settings are correctly registered. rietgors:# cd /sys/devices/pci0000:00/0000:00:08.1/0000:05:00.0/backlight/acpi_video0 Before: rietgors:# cat actual_brightness max_brightness 21 49 After: rietgors:# cat actual_brightness max_brightness 36 49 Oddly, the max_brightness value is now 49. But in the scenario where I *do* have brightness control (acpi=off), the max_brightness value is 255. Exactly the same happens when I directly echo values in the "brightness" device from the command line. No change in brightness but an immediate popup of the external monitor widget. [*] For ease of reference: these are the last 4 lines from the boot log if the laptop hangs: [drm] amdgpu kernel modesetting enabled. Virtual CRAT table created for CPU amdgpu: Topology: Add CPU node fb0: switching to amdgpudrmfb from EFI VGA Please be aware: I think I'm computer savvy, but working with or on the kernel is way out of my comfort zone. I'd be happy to investigate and try further. But I probably will need detailed instructions. Thanks, Koos </body> </html>