backlight control too laggy, barely usable
ls /sys/class/backlight/
acpi_video0 intel_backlight
Tried every acpi_backlight parameter. Also 4.20.3 and 4.19.16 kernels, to no avail.
The controls are indeed working but with a lag of about a second between adjustments:
Feb 07 12:22:49 carlos pkexec[7219]: carlos: Executing command [USER=root] [TTY=unknown] [CWD=/home/carlos] [COMMAND=/usr/lib/gsd-backlight-helper --set-brightness 64]
Feb 07 12:22:54 carlos pkexec[7242]: pam_unix(polkit-1:session): session opened for user root by (uid=1000)
Feb 07 12:22:54 carlos pkexec[7242]: carlos: Executing command [USER=root] [TTY=unknown] [CWD=/home/carlos] [COMMAND=/usr/lib/gsd-backlight-helper --set-brightness 60]
Feb 07 12:22:55 carlos pkexec[7248]: pam_unix(polkit-1:session): session opened for user root by (uid=1000)
Feb 07 12:22:55 carlos pkexec[7248]: carlos: Executing command [USER=root] [TTY=unknown] [CWD=/home/carlos] [COMMAND=/usr/lib/gsd-backlight-helper --set-brightness 56]
Calling gsd-backlight-helper as root from the command line is indeed quite fast:
for b in 64 60 56; do time /usr/lib/gsd-backlight-helper --set-brightness $b; done
real 0m0.085s
user 0m0.000s
sys 0m0.010s
real 0m0.046s
user 0m0.000s
sys 0m0.010s
real 0m0.047s
user 0m0.004s
sys 0m0.004s
But as an unpriviledged user via pkexec things become slower:
time for b in 64 60 56; do pkexec /usr/lib/gsd-backlight-helper --set-brightness $b; done
real 0m1.581s
user 0m0.526s
sys 0m0.860s
Edited by Carlos Pita