Messages in this thread | | | Date | Mon, 6 Mar 2006 22:44:26 +0100 | From | Pavel Machek <> | Subject | Re: RFC: Backlight Class sysfs attribute behaviour |
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On Po 06-03-06 09:00:27, Antonino A. Daplas wrote: > Richard Purdie wrote: > > At present, the backlight class presents two attributes to sysfs, > > brightness and power. I'm a little confused as to whether these > > attributes are currently doing the right things. > > > > Taking brightness, at any one time we have several different brightness > > values: > > > > * User requested brightness (echo y > /sys/class/backlight/xxx/brightness) > > * Driver determined brightness which accounts for things like FB > > blanking, low battery backlight limiting (an example from corgi_bl), > > user requested power state, device suspend/resume. > > > > The solution might be to have brightness always return the user > > requested value y and have a new attribute returning the brightness as > > determined by the driver once it accounts for all the factors it needs > > to consider. Naming of such an attribute is tricky - "driver_brightness" > > perthaps? > > Why not just agree on a normal range of values (ie, 0-255), and let the > driver "denormalize" them? Thus, a driver that has only 2 levels of > brightness, will treat 0-127 as 0 and 128-255 as 1, and will return only > two possible values 0 and 255.
Does not work... how do you set minimum brightness with backlight on (so that text is visible)? Pavel -- Web maintainer for suspend.sf.net (www.sf.net/projects/suspend) wanted... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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