This is a weird bug. On my machine, I discovered that I can predict that brightness level change by using xbacklight. I don't know how xbacklight works, but it does not follow the brightness changes I get when pressing hotkeys. But the value of backlight brightness that xbacklight reports is always the brightness level that is set when a) starting a virtual machine b) restoring the screen after closing and opening the lid c) doing xset dpms force on
Also, if the backlight hotkeys changed backlight brightness via xbacklight, then there would be no bug. xbacklight needs to be installed from synaptic. ----- I have 8 levels of brightness, so my first steps in % are 0, 14, 29 via the hotkeys, I make the display 100% bright # xbacklight -get 0.000000 : so it doesn't know the screen has changed # xbacklight -set 10 : no change; the backlight stays at 100% #xbacklight -set 20 : the backlight dims to the second lowest level (that is, it goes to level 14%) #xbacklight -get 14.285714 again, use the hotkeys to go to 100%. Then ... #xbacklight -get 14.285714 #xbacklight -set 20 doesn't do anything but #xbacklight -set 50 #xbacklight -set 20 does get my back to the second level. alternatively, I can do xset dpms force on because this always forces the backlight to be the same value as xbacklight -get; it overrides whatever setting the user has chosen via the hotkeys. Or to put it another way, however xbacklight works does not update itself when the user changes the backlight with the hotkeys. and here is the link to the original bug report: the brightness level that you get by starting a virtual machine is the same as you get by xset dpms force on That is, you can always predict the brightness level you will get when starting a virtualbox-ose virtual machine by first checking xbacklight -get -- Starting up a virtual machine in a virtualbox changes the display brightness (again) https://bugs.launchpad.net/bugs/241195 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
