Re: [PATCH v2 1/4] opp: core: add regulators enable and disable

Viresh Kumar
2019-07-16T10:05:47Z

On 15-07-19, 14:04, Kamil Konieczny wrote:
> Add enable regulators to dev_pm_opp_set_regulators() and disable
> regulators to dev_pm_opp_put_regulators(). This prepares for
> converting exynos-bus devfreq driver to use dev_pm_opp_set_rate().
>
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> --
> Changes in v2:
>
> - move regulator enable and disable into loop
>
> ---
> drivers/opp/core.c | 18 +++++++++++++++---
> 1 file changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 0e7703fe733f..069c5cf8827e 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1570,6 +1570,10 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
> goto free_regulators;
> }
>
> + ret = regulator_enable(reg);
> + if (ret < 0)
> + goto disable;

The name of this label is logically incorrect because we won't disable
the regulator from there but put it. Over that, I would rather prefer
to remove the label and add regulator_put() here itself.

> +
> opp_table->regulators[i] = reg;
> }
>
> @@ -1582,9 +1586,15 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>
> return opp_table;
>
> +disable:
> + regulator_put(reg);
> + --i;
> +
> free_regulators:
> - while (i != 0)
> - regulator_put(opp_table->regulators[--i]);
> + for (; i >= 0; --i) {
> + regulator_disable(opp_table->regulators[i]);
> + regulator_put(opp_table->regulators[i]);

This is incorrect as this will now try to put/disable the regulator
which we failed to acquire. As --i happens only after the loop has run
once. You can rather do:

while (i--) {
regulator_disable(opp_table->regulators[i]);
regulator_put(opp_table->regulators[i]);
}

> + }
>
> kfree(opp_table->regulators);
> opp_table->regulators = NULL;
> @@ -1610,8 +1620,10 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
> /* Make sure there are no concurrent readers while updating opp_table */
> WARN_ON(!list_empty(&opp_table->opp_list));
>
> - for (i = opp_table->regulator_count - 1; i >= 0; i--)
> + for (i = opp_table->regulator_count - 1; i >= 0; i--) {
> + regulator_disable(opp_table->regulators[i]);
> regulator_put(opp_table->regulators[i]);
> + }
>
> _free_set_opp_data(opp_table);
>
> --
> 2.22.0

--
viresh