Re: [PATCH] clk: tegra: Return the exact clock rate from clk_round_rate

[Peter De Schrijver <pdeschrijver@nvidia.com>]

On Fri, Sep 21, 2018 at 06:01:49PM -0400, ryang wrote:
> The current behavior is that clk_round_rate would return the same clock
> rate passed to it for valid PLL configurations. This change will return
> the exact rate the PLL will provide in accordance with clk API.
> 
> Signed-off-by: ryang <decatf@gmail.com>
> ---
>  drivers/clk/tegra/clk-pll.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
> index 17a058c3bbc1..36014a6ec42e 100644
> --- a/drivers/clk/tegra/clk-pll.c
> +++ b/drivers/clk/tegra/clk-pll.c
> @@ -595,7 +595,12 @@ static int _calc_rate(struct clk_hw *hw, struct tegra_clk_pll_freq_table *cfg,
>  		return -EINVAL;
>  	}
>  
> -	cfg->output_rate >>= p_div;
> +	if (cfg->m == 0) {
> +		cfg->output_rate = 0;

I think a WARN_ON() is appropriate here. the input divider should never be 0.

Peter.

> +	} else {
> +		cfg->output_rate = cfg->n * DIV_ROUND_UP(parent_rate, cfg->m);
> +		cfg->output_rate >>= p_div;
> +	}
>  
>  	if (pll->params->pdiv_tohw) {
>  		ret = _p_div_to_hw(hw, 1 << p_div);
> -- 
> 2.17.1
>