Re: [PATCH 08/25] serial: sh-sci: Make unsigned values in sci_baud_calc_hscif() unsigned

Laurent Pinchart
2015-11-19T20:36:11Z

Hi Geert,

Thank you for the patch.

On Thursday 19 November 2015 19:38:47 Geert Uytterhoeven wrote:
> Move the -1 offset of br to the assignment to *brr, so br cannot become
> negative anymore, and update the clamp() call. Now all unsigned values
> in sci_baud_calc_hscif() can become unsigned.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> drivers/tty/serial/sh-sci.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index 9442961a198378c7..fba1e1eea15dc3a1 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -1870,7 +1870,8 @@ static unsigned int sci_scbrr_calc(struct sci_port *s,
> unsigned int bps, static void sci_baud_calc_hscif(unsigned int bps,
> unsigned long freq, int *brr, unsigned int *srr, unsigned int *cks)
> {
> - int sr, c, br, err, recv_margin;
> + unsigned int sr, br, c;
> + int err, recv_margin;
> int min_err = 1000; /* 100% */
> int recv_max_margin = 0;
>
> @@ -1880,9 +1881,9 @@ static void sci_baud_calc_hscif(unsigned int bps,
> unsigned long freq, int *brr, for (c = 0; c <= 3; c++) {
> /* integerized formulas from HSCIF documentation */
> br = DIV_ROUND_CLOSEST(freq, (sr *
> - (1 << (2 * c + 1)) * bps)) - 1;
> - br = clamp(br, 0, 255);
> - err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr *
> + (1 << (2 * c + 1)) * bps));
> + br = clamp(br, 1U, 256U);
> + err = DIV_ROUND_CLOSEST(freq, (br * bps * sr *
> (1 << (2 * c + 1)) / 1000)) -
> 1000;

While you're at it you can remove the parentheses around the second argument
to DIV_ROUND_CLOSEST, they're not needed.

> /* Calc recv margin
> @@ -1908,7 +1909,7 @@ static void sci_baud_calc_hscif(unsigned int bps,
> unsigned long freq, int *brr, else
> continue;
>
> - *brr = br;
> + *brr = br - 1;
> *srr = sr - 1;
> *cks = c;
> }

--
Regards,

Laurent Pinchart