=- Michael Biebl wrote on Tue 15.Oct'19 at 13:33:15 +0200 -= > I can get the current brightness via > > # cat /sys/class/backlight/intel_backlight/brightness > > 1500
I get 79560. > and change it via > > # echo 2000 > /sys/class/backlight/intel_backlight/brightness Setting it via intel to 66666 makes it darker. > What's the output you get for your dell_backlight? >From dell_backlight I get: # cat dell_backlight/brightness 6 But when setting it, it says: # echo 5 > dell_backlight/brightness -ksh: echo: write to 1 failed [Input/output error] This is what both links look like: 0 lrwxrwxrwx 1 root root 0 Oct 16 05:01 dell_backlight -> ../../devices/platform/dell-laptop/backlight/dell_backlight/ 0 lrwxrwxrwx 1 root root 0 Oct 16 04:54 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/ dell_backlight/: total 0 0 -r--r--r-- 1 root root 4096 Oct 16 05:03 actual_brightness 0 -rw-r--r-- 1 root root 4096 Oct 16 05:03 bl_power 0 -rw-r--r-- 1 root root 4096 Oct 16 05:04 brightness 0 lrwxrwxrwx 1 root root 0 Oct 16 05:03 device -> ../../../dell-laptop/ 0 -r--r--r-- 1 root root 4096 Oct 16 05:03 max_brightness 0 drwxr-xr-x 2 root root 0 Oct 16 05:03 power/ 0 lrwxrwxrwx 1 root root 0 Oct 16 04:52 subsystem -> ../../../../../class/backlight/ 0 -r--r--r-- 1 root root 4096 Oct 16 05:03 type 0 -rw-r--r-- 1 root root 4096 Oct 16 05:03 uevent intel_backlight/: total 0 0 -r--r--r-- 1 root root 4096 Oct 16 04:54 actual_brightness 0 -rw-r--r-- 1 root root 4096 Oct 16 04:54 bl_power 0 -rw-r--r-- 1 root root 4096 Oct 16 04:54 brightness 0 lrwxrwxrwx 1 root root 0 Oct 16 04:54 device -> ../../card0-LVDS-1/ 0 -r--r--r-- 1 root root 4096 Oct 16 04:54 max_brightness 0 drwxr-xr-x 2 root root 0 Oct 16 04:54 power/ 0 lrwxrwxrwx 1 root root 0 Oct 16 04:54 subsystem -> ../../../../../../../class/backlight/ 0 -r--r--r-- 1 root root 4096 Oct 16 04:54 type 0 -rw-r--r-- 1 root root 4096 Oct 16 04:54 uevent What next?
