Hello Matthias,
On 03/24/2017 05:38 PM, Brian Norris wrote:
> On Fri, Mar 24, 2017 at 01:09:52PM -0700, Matthias Kaehlcke wrote:
>> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
>> index 53d4fc70dbd0..121838e0125b 100644
>> --- a/drivers/regulator/core.c
>> +++ b/drivers/regulator/core.c
>> @@ -2487,6 +2487,10 @@ static int _regulator_list_voltage(struct regulator
>> *regulator,
>> if (lock)
>> mutex_unlock(&rdev->mutex);
>> } else if (rdev->supply) {
>> + // Limit propagation of parent values to switch regulators
>
> The kernel doesn't use C99 comments. Oddly enough, this isn't actually
+1
> in the coding style doc (Documentation/process/coding-style.rst), nor is
> it caught by scripts/checkpatch.pl (even though it clearly has a 'C99
> comment' rule).
>
>> + if (ops->get_voltage || ops->get_voltage_sel)
It's valid to have a .get_voltage_sel callback without a .list_voltage?
At least it seems that _regulator_get_voltage() assumes that having a
.get_voltage_sel implies that a .list_voltage will also be available.
static int _regulator_get_voltage(struct regulator_dev *rdev)
{
...
if (rdev->desc->ops->get_voltage_sel) {
sel = rdev->desc->ops->get_voltage_sel(rdev);
if (sel < 0)
return sel;
ret = rdev->desc->ops->list_voltage(rdev, sel);
} else if (rdev->desc->ops->get_voltage) {
...
}
So I would only check for if (ops->get_voltage).
>> + return -EINVAL;
>> +
>> ret = _regulator_list_voltage(rdev->supply, selector, lock);
>> } else {
>> return -EINVAL;
>> @@ -2540,6 +2544,7 @@ EXPORT_SYMBOL_GPL(regulator_is_enabled);
>> int regulator_count_voltages(struct regulator *regulator)
>> {
>> struct regulator_dev *rdev = regulator->rdev;
>> + const struct regulator_ops *ops = rdev->desc->ops;
>>
>> if (rdev->desc->n_voltages)
>> return rdev->desc->n_voltages;
>> @@ -2547,6 +2552,10 @@ int regulator_count_voltages(struct regulator
>> *regulator)
>> if (!rdev->supply)
>> return -EINVAL;
>>
>> + // Limit propagation of parent value to switch regulators
>
> Same here.
>
>> + if (ops->get_voltage || ops->get_voltage_sel || ops->list_voltage)
>> + return -EINVAL;
>> +
I wonder if instead of always checking if the regulator lacks operations,
it wouldn't be better to do it just once and store that the regulator is
a switch so that state can be used as explicit check for switch instead.
Something like if (!rdev->supply || !rdev->switch) looks more clear to me.
>> return regulator_count_voltages(rdev->supply);
>> }
>> EXPORT_SYMBOL_GPL(regulator_count_voltages);
>
> I'm not very familiar with this code, but judging by your problem
> description in previous threads and by comparing with the logic in
> _regulator_get_voltage() (for when to reference the ->supply), this
> seems resonable. So:
>
> Reviewed-by: Brian Norris <briannor...@chromium.org>
>
Agreed, the logic sounds reasonable indeed and I didn't think of this
case when writing the mentioned commit, so feel free to add:
Reviewed-by: Javier Martinez Canillas <jav...@osg.samsung.com>
> It's probably worth verifying that this doesn't break whatever Javier
> was supporting in the first place, as a sanity check.
>
I've tested in the system that led to the mentioned commit and I did
not find any issue with $SUBJECT.
Tested-by: Javier Martinez Canillas <jav...@osg.samsung.com>
> Brian
>
Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
