Messages in this thread | | | Date | Mon, 9 Oct 2023 16:18:08 +0300 | From | Dmitry Rokosov <> | Subject | Re: [PATCH v1 09/11] leds: aw200xx: improve autodim calculation method |
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On Fri, Oct 06, 2023 at 09:03:47PM +0300, Andy Shevchenko wrote: > On Fri, Oct 6, 2023 at 7:05 PM Dmitry Rokosov > <ddrokosov@salutedevices.com> wrote: > > > > From: George Stark <gnstark@salutedevices.com> > > > > use DIV_ROUND_UP instead of coarse div > > Please, respect English grammar and punctuation. > Refer to macros and functions as func() (note the parentheses). > > ... > > > #define AW200XX_REG_DIM2FADE(x) ((x) + 1) > > +#define AW200XX_REG_FADE2DIM(fade) \ > > + DIV_ROUND_UP((fade) * AW200XX_DIM_MAX, AW200XX_FADE_MAX) > > Have you checked if the overflow is _now_ possible (compiling on > 32-bit platforms as well)?
I suppose we shouldn't carry on about overflow here because the value of fade cannot exceed 255, and DIM_MAX is set at 63
You can find maximum values of fade and dim in the aw200xx driver header:
#define AW200XX_DIM_MAX (BIT(6) - 1) #define AW200XX_FADE_MAX (BIT(8) - 1)
-- Thank you, Dmitry
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