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SubjectRe: [PATCH v3 3/3] b43: Use cordic algorithm from kernel library
On Wed, Nov 14, 2018 at 07:46:28PM +0100, Michael Büsch wrote:
> On Wed, 14 Nov 2018 20:27:52 +0200
> Priit Laes <plaes@plaes.org> wrote:
>
> > Kernel library has a common cordic algorithm which is identical
> > to internally implementatd one, so use it and drop the duplicate
> > implementation.
>
>
> In v2 of the series it has been said that:
>
> Arend van Spriel <arend.vanspriel@broadcom.com> wrote:
> > I recall doing a comparison between the algorithms and thought I put
> > that in the original commit message. However, it is not there. It is not
> > exactly the same as in b43 so there are difference for certain angles,
> > most results are the same however. This implementation is slightly more
> > accurate on the full scale.
>
>
> That's not my definition of "identical".
>
> Please do not apply this patch without doing a thorough regression test
> on actual b43 LP hardware.

Indeed, there's a big discrepancy in the results of both algorithms.

Here's the test script:
https://gist.github.com/plaes/284993a4fc65e0926d0628a11f0cf874

So at current state, this is self-NAK from me too and this patch should
be dropped.

>
> --
> Michael


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