Comment 27 for bug 1261853

A customer of mine gave me his old notebook because he bought a new one. The laptop is running an p to date Xubuntu 13.10 64bit. Now I'm suffering similar issue with brightness control: when I press the appropriate keys on keyboard the slide appears on the upper right corner of the screen but even if it changes the setting has no effect on the system . The notebook I have has an Intel X3100 integrated video

00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) (rev 0c)

I tried different combinations on grub but no one resolved the issue. Problem is I have not intel_backlight on /sys/class/backlight folder but just acpi_video0 or dell_backlight (if I set acpi_backlight=vendor on grub).

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effe@Vostro1310:/sys/class/backlight$ for i in /sys/class/backlight/*; do echo -e "\n $i"; cat $i/{brightness,max_brightness,actual_brightness}; done

 /sys/class/backlight/dell_backlight
1
7
1
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If I increase the backlight the files are correctly updated:

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 /sys/class/backlight/dell_backlight
7
7
7
------------------
acpi_listen works just on new mainline kernel 3.13.2 (tried bot generic and lowlatency) on stock kernel there isn't output at all:

video/brightnessup BRTUP 00000086 00000000 K
video/brightnessup BRTUP 00000086 00000000 K
video/brightnessup BRTUP 00000086 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K

Now I'm using xrandr to change the brightness:

effe@Vostro1310:/sys/class/backlight$ xrandr --output LVDS1 --brightness 0.5

What can I try to triage the issue?

Thanks.