Hi Thierry,
On 07/04/16 15:22, Thierry Reding wrote:
> From: Thierry Reding <[email protected]>
>
> Subsequent patches will need access to the parent supply from within the
> set_machine_constraints() function to properly implement bypass mode. If
> the parent supply hasn't been resolved by that time the voltage can't be
> queried.
>
> Also, by making sure the supply is resolved early most of the changes in
> set_machine_constraints() don't have to be undone if resolution fails.
>
> Suggested-by: Mark Brown <[email protected]>
> Signed-off-by: Thierry Reding <[email protected]>
> ---
> drivers/regulator/core.c | 27 +++++++++++++++++++++------
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 2786d251b1cc..cc0333a79924 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -3972,18 +3972,27 @@ regulator_register(const struct regulator_desc
> *regulator_desc,
>
> dev_set_drvdata(&rdev->dev, rdev);
>
> + if (init_data && init_data->supply_regulator)
> + rdev->supply_name = init_data->supply_regulator;
> + else if (regulator_desc->supply_name)
> + rdev->supply_name = regulator_desc->supply_name;
> +
> + /*
> + * set_machine_constraints() needs the supply to be resolved in order
> + * to support querying the current voltage in bypass mode. Resolve it
> + * here to more easily handle deferred probing.
> + */
> + ret = regulator_resolve_supply(rdev);
> + if (ret < 0)
> + goto scrub;
> +
Thanks for sending this. However, I think that calling
regulator_resolve_supply() can cause a deadlock, because the
regulator_list_mutex is held at this point and
regulator_resolve_supply() calls regulator_dev_lookup() which may try to
request the mutex again.
So may be we need to move this call after the call to
regulator_of_get_init_data() before we acquire the mutex.
Also, if we add this call, then I am wondering if we still need ...
class_for_each_device(®ulator_class, NULL, NULL,
regulator_register_resolve_supply);
Cheers
Jon
