Re: [PATCH v8 01/34] opp: Add dev_pm_opp_sync() helper

Viresh Kumar
2021-08-17T07:55:23Z

On 17-08-21, 04:27, Dmitry Osipenko wrote:
> Add dev_pm_opp_sync() helper which syncs OPP table with hardware state
> and vice versa.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/opp/core.c | 42 +++++++++++++++++++++++++++++++++++++++---
> include/linux/pm_opp.h | 6 ++++++
> 2 files changed, 45 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 5543c54dacc5..18016e49605f 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -939,7 +939,8 @@ static int _set_required_opps(struct device *dev,
> return ret;
> }
>
> -static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
> +static struct dev_pm_opp *
> +_find_current_opp(struct device *dev, struct opp_table *opp_table)
> {
> struct dev_pm_opp *opp = ERR_PTR(-ENODEV);
> unsigned long freq;
> @@ -961,7 +962,7 @@ static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
> mutex_unlock(&opp_table->lock);
> }
>
> - opp_table->current_opp = opp;
> + return opp;
> }
>
> static int _disable_opp_table(struct device *dev, struct opp_table *opp_table)
> @@ -1003,7 +1004,7 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
>
> /* Find the currently set OPP if we don't know already */
> if (unlikely(!opp_table->current_opp))
> - _find_current_opp(dev, opp_table);
> + opp_table->current_opp = _find_current_opp(dev, opp_table);
>
> old_opp = opp_table->current_opp;
>
> @@ -2931,3 +2932,38 @@ int dev_pm_opp_sync_regulators(struct device *dev)
> return ret;
> }
> EXPORT_SYMBOL_GPL(dev_pm_opp_sync_regulators);
> +
> +/**
> + * dev_pm_opp_sync() - Sync OPP state
> + * @dev: device for which we do this operation
> + *
> + * Initialize OPP table accordingly to current clock rate or
> + * first available OPP if clock not available for this device.
> + *
> + * Return: 0 on success or a negative error value.
> + */
> +int dev_pm_opp_sync(struct device *dev)
> +{
> + struct opp_table *opp_table;
> + struct dev_pm_opp *opp;
> + int ret = 0;
> +
> + /* Device may not have OPP table */
> + opp_table = _find_opp_table(dev);
> + if (IS_ERR(opp_table))
> + return 0;
> +
> + if (!_get_opp_count(opp_table))
> + goto put_table;
> +
> + opp = _find_current_opp(dev, opp_table);
> + ret = _set_opp(dev, opp_table, opp, opp->rate);

And I am not sure how this will end up working, since new OPP will be
equal to old one. Since I see you call this from resume() at many
places.

what exactly are you trying to do here ? Those details would be good
to have in commit log as well, I haven't really followed V7 of your
series.

--
viresh