Re: [RFC PATCH 3/3] cpufreq: imx6q: refine clk operations

From: Leonard Crestez
Date: Tue Apr 11 2017 - 13:48:48 EST


On Wed, 2017-04-12 at 12:03 +0800, Dong Aisheng wrote:
> +static int num_clks;
> +static struct clk_bulk_data clks[] = {
> + { .id = "arm" },
> + { .id = "pll1_sys" },
> + { .id = "step" },
> + { .id = "pll1_sw" },
> + { .id = "pll2_pfd2_396m" },
> + { .id = "pll2_bus" },
> + { .id = "secondary_sel" },
> +};

The .id is only required for initialization, it seems strange to keep
it around runtime data. It might be better for this API to work with an
array of clk* and separate array of names (or clk_bulk_init_data if we
need flags). Variable references would be shorter and it would allow
more data to be const.

> -put_clk:
> - if (!IS_ERR(arm_clk))
> - clk_put(arm_clk);
> - if (!IS_ERR(pll1_sys_clk))
> - clk_put(pll1_sys_clk);
> - if (!IS_ERR(pll1_sw_clk))
> - clk_put(pll1_sw_clk);
> - if (!IS_ERR(step_clk))
> - clk_put(step_clk);
> - if (!IS_ERR(pll2_pfd2_396m_clk))
> - clk_put(pll2_pfd2_396m_clk);
> - if (!IS_ERR(pll2_bus_clk))
> - clk_put(pll2_bus_clk);
> - if (!IS_ERR(secondary_sel_clk))
> - clk_put(secondary_sel_clk);
> +
> + clk_bulk_put(num_clks, clks);
> +put_node:
> Â of_node_put(np);
> +
> Â return ret;
> Â}


My subjective opinion is that a better way to clean this up would be to
have a single imx6q_cpufreq_clean function that takes all resources and
does stuff like:

if (!IS_ERR(clk)) clk_put(clk);
clk = NULL;

That function can be called from both _remove and failed _probe without
having to keep track of which resources have been allocated until then.
Just free and NULL all clocks/regulators and simplify control flow.

--
Regards,
Leonard