[945GME] wrong scale for backlight with Xfce
Submitted by Rpnpif
Assigned to Chris Wilson @ickle
Description
The scale of change of the intensity of the backlight is wrong.
Changing this is done with the hot keys to increase or decrease.
The minimum get a black screen.
cat /sys/class/backlight/eeepc/brigthness
0
cat /sys/class/backlight/intel_backlight/brigthness
0
1st press on the hot key : get also a black screen.
cat /sys/class/backlight/eeepc/brigthness
1
cat /sys/class/backlight/intel_backlight/brigthness
79787
2nd press : get a medium intensity.
cat /sys/class/backlight/eeepc/brigthness
2
cat /sys/class/backlight/intel_backlight/brigthness
159374
3rd to 12th press get a normal change of the backlight.
To : 796875
But the intensity of the 12th is less than the 11th.
Expected :
The minimum should not light off the screen.
/sys/class/backlight/intel_backlight/brigthness
159374
From /sys/class/backlight/eeepc/brigthness=1 to 10 or 12, the backlight
should change linearly without light off.
This buggy behaviour was seen only with Xfce, not with lightdm or the Linux
console.
Chipset: 945GME
Architecture: X86
Found in version xserver-xorg-video-intel/2:2.99.917+git20161105-1~bpo8+1 from Debian Jessie-backports.
Works fine with older versions.
Machine:Eeepc 901.
Reproducible : always.
See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=846882