Re: [PATCH] clk: tegra: Return the exact clock rate from clk_round_rate
From: Peter De Schrijver
Date: Mon Sep 24 2018 - 04:08:12 EST
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@xxxxxxxxx>
> ---
> 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
>