Hi, >> Well, the ACPI spec says this (section B.5.2): >> >> " >> The OEM may define the number 0 as "Zero brightness" that can mean >> to turn off the lighting (e.g. LCD panel backlight) in the device. >> This may be useful in the case of an output device that can still be >> viewed using only ambient light, for example, a transflective LCD. >> " >> >> My interpretation of this is that the value 0 is supposed to still >> be visible. I'm pretty sure I saw a statement that 0 is supposed to >> mean "barely visible" somewhere, but can't find it at the moment. >> I'll search for the source of it. > > I think that's a stretch - "This may be useful" isn't normative > language, "The OEM may define" is. But even if we do assert it for the > ACPI backlight, it's not true for other interfaces - zero backlight > intensity is supposed to be screen off on Apple hardware, for instance. OK, I see. And there is user space depending on that behaviour? And again - how is user space supposed to know about the behavioral differences? Is it something like 'if type is raw, don't expect anything'? The reason for my question is that I want to determine what a) the correct place to fix this and b) the correct fix is. As Xrandr abstracts away the used backlight interface, I see no way for user space using Xrandr (e.g. KDE) to meaningfully handle this. Thanks, Danny
