[PATCH v2 3/4] ARM: dts: imx6qdl-colibri: backlight pwm: Simplify inverted backlight

Fabio Estevam festevam at gmail.com
Wed May 11 06:35:20 PDT 2022


On Wed, May 11, 2022 at 10:32 AM Max Krummenacher <max.oss.09 at gmail.com> wrote:

> I disagree. Just setting the invert without at the same changing the
> brightness-levels does
> change the user experience way more than when one adapts the available
> duty cycles
> at the same time.
>
> With the change to use the PWM with inverted polarity the PWM signals
> is inverted to
> how it was before this patch. Keeping the brightness-levels will then
> have a big brightness
> jump from 0 to 127 duty cycle, the other 6 steps will then be barely noticable.
>
> I.e. before the change the brightness for level [0..7] was
> ['off', 128/255, 64/255, 32/255, 16/255, 8/255, 4/255, 'off'],
> if one only inverts the polarity it will be
> ['off', 128/255, 191/255, 223/255, 239/255, 247/255, 255/255].
> With the proposed patch it will be
> ['off', 4/255, 8/255, 16/255, 32/255, 64/255, 128/255, 255/255].

Ok, please add an explanation to the commit log as to why you are
changing the brightness levels
like you did here. Thanks



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