Re: [PATCH 1/3] opp: core: add regulators enable and disable

[Kamil Konieczny]

On 10.07.2019 12:16, Kamil Konieczny wrote:
> 
> 
> On 09.07.2019 07:40, Viresh Kumar wrote:
>> On 08-07-19, 16:11, k.konieczny@xxxxxxxxxxxxxxxxxxx wrote:
>>> From: Kamil Konieczny <k.konieczny@xxxxxxxxxxxxxxxxxxx>
>>>
>>> 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@xxxxxxxxxxxxxxxxxxx>
>>> ---
>>>  drivers/opp/core.c | 13 +++++++++++++
>>>  1 file changed, 13 insertions(+)
>>>
>>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>>> index 0e7703fe733f..947cac452854 100644
>>> --- a/drivers/opp/core.c
>>> +++ b/drivers/opp/core.c
>>> @@ -1580,8 +1580,19 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
>>>  	if (ret)
>>>  		goto free_regulators;
>>>  
>>> +	for (i = 0; i < opp_table->regulator_count; i++) {
>>> +		ret = regulator_enable(opp_table->regulators[i]);
>>> +		if (ret < 0)
>>> +			goto disable;
>>> +	}
>>
>> I am wondering on why is this really required as this isn't done for
>> any other platform, probably because the regulators are enabled by
>> bootloader and are always on.
> 
> It was not enabled for historical reasons, from design point regualtors
> should be enabled before use.
 
On Exynos platform devfreq driver (exynos-bus) always enabled them,
so I wanted to preserve the current behaviour.

I've also checked the change with cpufreq-dt driver and it doesn't cause
issues.

Do you find this change acceptable?


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