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SubjectRe: [PATCH] serial: sh-sci: Fix HSCIF RX sampling point calculation

> On April 1, 2019 at 1:25 PM Geert Uytterhoeven <geert+renesas@glider.be> wrote:
>
>
> There are several issues with the formula used for calculating the
> deviation from the intended rate:
> 1. While min_err and last_stop are signed, srr and baud are unsigned.
> Hence the signed values are promoted to unsigned, which will lead
> to a bogus value of deviation if min_err is negative,
> 2. Srr is the register field value, which is one less than the actual
> sampling rate factor,
> 3. The divisions do not use rounding.
>
> Fix this by casting unsigned variables to int, adding one to srr, and
> using a single DIV_ROUND_CLOSEST().
>
> Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>

CU
Uli

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