https://bugzilla.kernel.org/show_bug.cgi?id=216138
Bug ID: 216138
Summary: nvidia-wmi-ec-backlight Backlight regression
Product: ACPI
Version: 2.5
Kernel Version: 5.17
Hardware: Other
OS: Linux
Tree: Mainline
Status: NEW
Severity: high
Priority: P1
Component: EC
Assignee: acpi...@kernel-bugs.osdl.org
Reporter: silvasm...@gmail.com
Regression: No
Created attachment 301182
--> https://bugzilla.kernel.org/attachment.cgi?id=301182&action=edit
dmesg
Brightness control does not work with AMD Ryzen 5600h when using switchable
graphics (aka. Hybrid graphics). I currently using a Dell G15 5515 with fedora
36 and Kernel 5.17.
CPU: AMD Ryzen 5 5600h with Radeon Graphics
GPU: NVIDIA RTX 3050 Mobile Graphics
System Memory: 16 GB
Display(s): Laptop (Laptop Screen) and Dell secondary Monitor
How to reproduce the issue:
Enable hybrid graphics/Optimus in BIOS setup, so that the display will be
connected to the AMD GPU.
Try to change brightness from GNOME or write into
/sys/class/backlight/amdgpu_bl1/brightness. The display brightness doesn't
change.
Looking inside /sys/class/backlight/, there is only one directory amdgpu_bl1.
max_brightness is 255. actual_brightness follows the value written into
brightness.
The amdgpu.backlight=0 kernel parameter mentioned in #1438 (closed) doesn't
help here.
acpi_backlight=vendor or acpi_backlight=native or acpi_backlight=none makes no
difference. With acpi_backlight=video there is another acpi_video0 in addition
to amdgpu_bl1 in /sys/class/backlight/ but neither of them has any effect.
If hybrid graphics is disabled, the display is connected to the Nvidia GPU, the
Nvidia proprietary driver can change the display brightness without problem. In
this case there is only nvidia_0 in /sys/class/backlight/ with max_brightness
100.
In Windows 10 OS and hybrid graphics mode, the brightness control works if the
AMD driver (21.6.1 downloaded from AMD website) is installed and enabled and it
doesn't work if the AMD driver is not installed or disabled, regardless of the
status of Nvidia driver too.
--
You may reply to this email to add a comment.
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
acpi-bugzilla mailing list
acpi-bugzilla@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
