[U-Boot] Illegal use of FP ops in clock_ti814x.c

Wolfgang Denk
2013-10-29T10:48:07Z

Dear M?ns Rullg?rd,

In message <yw1x8uxc28y9.fsf@unicorn.mansr.com> you wrote:
>
> >> Something like this should be equivalent. That said, it looks
> >> suspiciously like it's meant to simply do a division and round up. If
> >> that is the case, +225 should be +249. It probably makes no difference
> >> for the values actually encountered.
> >
> > Umm... this is the part which I do not understand.
> >
> > The original code adds 90%; you add 90%, too. However, to round up,
> > one usually adds only 50% ?
>
> Adding 50% would round to nearest. For integer division to round up,
> you must add one less than the divisor.

Agreed. But do we want to round up? The original code used +90%,
which is something else, too...

> > Where are these 90% coming from? Are they in any way meaningful, or
> > even critical?
>
> My guess is that it was someone's approximation of 249 / 250. I don't
> know the hardware, so it's conceivable that it really should be this
> way, although it seems unlikely.

Are you able to test such a modificationon actual hardware?

Best regards,

Wolfgang Denk

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