1.When on battery screen brightness drop to 50%, whick is okay .
2. After that I increase brightness with function keys to say 80%, which works ok.
3. After the screen dims, it returns back to 50% again but not 80% ie: the value set by the function keys.
How can this be fixed or is it related to MATE Desktop. Other desktops like unity, xfce, cinnamon works as expected.
This is the output of lspci | grep VGA
~ $ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Mobile
945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)