Op 25 nov 2008, om 19:46 heeft David Brownell het volgende geschreven:
On Tuesday 25 November 2008, Koen Kooi wrote:Regardless of what implementation you choose, it would be *great* ifpeople used the backlight class for things like backlights. /sys/ class/backlight/<foo>/brightness is such a nice standard that lots and lots of usespace tools rely on it.How about a standard LED driver (optionally with a brightness control) and the newish "backlight" trigger?
I googled a bit and poked Richard Purdie (CC'ed) and he says: "Thats not what the trigger was supposed to be used for
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Anyone using /sys/class/leds for backlight functionality is doing it plain wrong"
The backlight trigger was added for supporting non-backlight leds that 'need' to get turned on/off together with the backlight, not being the backlight itself.
There's a thread at [1] where Pavel Machek tries to make the same point. Having a led driver for the PWMs is neat, but please have the backlight one use the backlight class (e.g. KConfig option, runtime check, etc). As I said in my other mail having 2 different ways to control backlights will be *hell* for distributions and userspace. Just look at the the trouble the serial port names are causing on ARM.
regards, Koen [1] http://linux.derkeiler.com/Mailing-Lists/Kernel/2008-10/threads.html#02359
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