Re: [PATCH] mmc: renesas_sdhi: Add margins for main clock and hs clock

[Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>]

Hi Biju,

> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index 6edbf5c161ab..539521f84e2f 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -128,6 +128,7 @@ static unsigned int renesas_sdhi_clk_update(struct tmio_mmc_host *host,
>         struct clk *ref_clk = priv->clk;
>         unsigned int freq, diff, best_freq = 0, diff_min = ~0;
>         unsigned int new_clock, clkh_shift = 0;
> +       unsigned int new_clock_margin;
>         int i;
>  
>         /*
> @@ -156,7 +157,9 @@ static unsigned int renesas_sdhi_clk_update(struct tmio_mmc_host *host,
>          */
>         for (i = min(9, ilog2(UINT_MAX / new_clock)); i >= 0; i--) {
>                 freq = clk_round_rate(ref_clk, new_clock << i);
> -               if (freq > (new_clock << i)) {
> +               new_clock_margin = (new_clock << i) + ((new_clock << i) >> 10);
> +
> +               if (freq > new_clock_margin) {

new_clock_margin needs a comment explaining why we need it and set it to
that particular value. Otherwise looks good to me.

Thanks for doing it,

   Wolfram

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