https://bugzilla.kernel.org/show_bug.cgi?id=198885 Bug ID: 198885 Summary: amdgpu.dc=1 on CIK (R4 Mullins APU) brightness impossible to change. by Fn or "echo". Product: Drivers Version: 2.5 Kernel Version: 4.15.4 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@xxxxxxxxxxxxxxxxxxxx Reporter: soprwa@xxxxxxxxx Regression: No Created attachment 274359 --> https://bugzilla.kernel.org/attachment.cgi?id=274359&action=edit dmesg with "amdgpu.dc=1" I am using gentoo ~amd64, kernel 4.15.4, amdgpu with amdgpu.dc=1 on CIK A6 APU - R4 Mullins. There is no possibility to change brightness level both with Fn keys or directly by an "echo" command, even as root when "amdgpu.dc=1" is set: ls -l /sys/class/backlight/amdgpu_bl0/ razem 0 -r--r--r-- 1 root root 4096 02-22 13:41 actual_brightness -rw-r--r-- 1 root root 4096 02-22 13:41 bl_power -rw-r--r-- 1 root root 4096 02-22 13:41 brightness lrwxrwxrwx 1 root root 0 02-22 13:41 device -> ../../../0000:00:01.0 -r--r--r-- 1 root root 4096 02-22 13:40 max_brightness drwxr-xr-x 2 root root 0 02-22 13:41 power lrwxrwxrwx 1 root root 0 02-22 13:40 subsystem -> ../../../../../class/backlight -r--r--r-- 1 root root 4096 02-22 13:40 type -rw-r--r-- 1 root root 4096 02-22 13:39 uevent "/sys/class/backlight/amdgpu_bl0 # echo 22 > actual_brightness bash: actual_brightness: permission denied" and "/sys/class/backlight/amdgpu_bl0 # echo 128 > brightness bash: echo: błąd zapisu: Bad argument" Without "amdgpu.dc=1" in kernel command line changing brightness level is working as expected, both Fn keys, and echoing directly to a file. I know that there are plans enabling amdgpu.dc by default, so impossibility to change brightness level IMHO is a big "no go". -- You are receiving this mail because: You are watching the assignee of the bug. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
