Re: [PATCH] leds: led-core: Get rid of enum led_brightness

From: Pavel Machek
Date: Thu Dec 17 2020 - 18:00:46 EST


Hi!

> > On Fri, 11 Dec 2020 03:48:40 +0200
> > Abanoub Sameh <abanoubsameh8@xxxxxxxxx> wrote:
> >
> > > This gets rid of enum led_brightness in the main led files,
> > > because it is deprecated, and an int can be used instead,
> > > or maybe even a uint8_t since it only goes up to 255.
> > > Next we can also patch the other files to get rid of it completely.
> >
> > 1. unsigned int should be used IMO
> > - using int may force all implementers to check for negative value
> > and return -EINVAL, which is stupid
> > - some LED controllers may offer more than 8bit brightness value, so
> > no uint8_t
>
> More than 8 bits would be good.
> While not really relevant for actual 'brightness' it allows
> for 'strange' things be encoded in the brightness field.

I have headlamp which can do 0.1lumens to 750lumens. Some go down to
0.01 lumens. More than 8 bits definitely makes sense.

Display backlights also need great ranges.

> While extra parameters could be added, they are only really usable
> by code that knows they are present.
> So encoding in the 'brightness' sort of makes sense.

No.
Pavel
--
http://www.livejournal.com/~pavelmachek

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