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

Kamil Konieczny
2019-07-17T14:15:07Z

On 16.07.2019 12:05, Viresh Kumar wrote:
> 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.

I will change this and following according to your suggestions and will send v3.

>> +
>> 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
>

--
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland