Hi Pavel, On Sun, Mar 8, 2015 at 9:57 PM, Pavel Machek <pavel@xxxxxx> wrote: > Ok, so I played with RGB LED a bit, and we have quite a gap in > documentation: what 50% brightness means is non-trivial and very > important in case we want to do smooth blinking and color transitions. > > Signed-off-by: Pavel Machek <pavel@xxxxxx> > > diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led > index 3646ec8..649d7a6 100644 > --- a/Documentation/ABI/testing/sysfs-class-led > +++ b/Documentation/ABI/testing/sysfs-class-led > @@ -8,6 +8,11 @@ Description: > non-zero brightness settings. The value is between 0 and > /sys/class/leds/<led>/max_brightness. > > + If LED supports continuous brightness settings, 50% brightness > + should correspond to 50% brightness perceived by human, in a similar > + manner pixel brightness on monitor does (not 50% PWM). How many drivers do it right? How many don't? For those that don't, perhaps we handle the conversion between perceived and pwm in the core, e.g. by adding a new flag to led_classdev.flags to indicate the need for conversion? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html