Re: [PATCH v2] drm: rcar-du: calculate DPLLCR to be more small jitter

[Geert Uytterhoeven]

Hi Laurent,

On Thu, Dec 14, 2017 at 9:17 AM, Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> On Thursday, 14 December 2017 04:10:27 EET Kuninori Morimoto wrote:
>> >> +                  if ((fvco < 2000) ||
>> >> +                      (fvco > 4096000000ll))
>> >
>> > No need for the inner parentheses, and you can write both conditions on a
>> > single line. Furthemore 4096 MHz will fit in a 32-bit number, so there's
>> > no need for the ll.
>>
>> Yes, but compiled by 32bit too, right ?
>> Without this "ll", 32bit compiler say
>>
>>       warning: this decimal constant is unsigned only in ISO C90
>
> That's right. How about 4096000000UL then, to force unsigned integer types ?
> Or possibly even better, 4096 * 1000 * 1000UL to make it more readable ?

If it's just about making the number unsigned, and not about 64-bit arithmetic,
a "U" suffix should be sufficient.

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