** Summary changed: - gnome-rr: Adjust the minimum brightness level when the maximum >= 100. + gnome-rr: Normalize the minimum brightness level.
** Description changed: - If the maximum brightness is equal to or bigger than 100, it has higher - possibility that zero is off. So adjusting the minimum brightness to avoid the problem. + This patch is aimed to normalize the minimum brightness level for 20 + brightness steps used in gnome-settings-daemon and bring a better and + consistent user experience for the brigtness control in + gnome-settings-daemon and gnome-control-center. + + For example, most Intel Haswell/Broadwell UMA laptops have the same 937 + value as their maximum brightness level on Linux kernel 3.16 by default. + + By this patch, the minimum brightness level will be changed to 17 + because 937 / 20 == 46 and 937 % 46 == 17, and 17 is a reasonable and + visible brightness level as the minimum brightness level on these laptops. + If we set 0 to /sys/class/backlight/intel_backlight/brightness, it makes + the screen off. + If we set 1 to /sys/class/backlight/intel_backlight/brightness, the + screen becomes hard to see the content. + So 17 is a better brightness level. + + This patch should not affect existing ACPI brightness control especially + for those laptops having the maximum brightness level under 20. + + This also avoided the screen off when using the minimum brightness level + under some condition. Quotes from http://cgit.freedesktop.org/xorg/proto/randrproto/tree/randrproto.txt "This property controls the brightness on laptop panels and equivalent displays with a backlight controller. The driver specific maximum value MUST turn the backlight to full brightness, 1 SHOULD turn the backlight to minimum brightness, 0 SHOULD turn the backlight off." Quotes from http://msdn.microsoft.com/en- us/library/windows/hardware/ff569755(v=vs.85).aspx "Brightness levels are represented as single-byte values in the range from zero to 100 where zero is off and 100 is the maximum brightness that a laptop computer supports. Every laptop computer must report a maximum brightness level of 100; however, a laptop computer is not required to support a level of zero. The only requirement for values from zero to 100 is that larger values must represent higher brightness levels." -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1340544 Title: gnome-rr: Normalize the minimum brightness level. To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-desktop/+bug/1340544/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
