Re: [PATCH 02/12] PM / OPP: Add 'struct kref' to OPP table

From: Stephen Boyd
Date: Mon Jan 09 2017 - 18:36:34 EST


On 12/07, Viresh Kumar wrote:
> @@ -894,8 +895,36 @@ static void _kfree_device_rcu(struct rcu_head *head)
> kfree_rcu(opp_table, rcu_head);
> }
>
> -static void _free_opp_table(struct opp_table *opp_table)
> +void _get_opp_table_kref(struct opp_table *opp_table)
> {
> + kref_get(&opp_table->kref);
> +}
> +
> +struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
> +{
> + struct opp_table *opp_table;
> +
> + /* Hold our table modification lock here */
> + mutex_lock(&opp_table_lock);
> +
> + opp_table = _find_opp_table(dev);
> + if (!IS_ERR(opp_table)) {
> + _get_opp_table_kref(opp_table);

It seems odd to have _get_opp_table_kref() take a pointer to
increment a kref on. It would be better to have _find_opp_table()
return the pointer with the reference already taken so that we
don't have to update callers with reference grabbing calls.
Typically if a function returns a reference counted pointer the
reference counting has already been done.

> + goto unlock;
> + }
> +
> + opp_table = _allocate_opp_table(dev);
> +
> +unlock:
> + mutex_unlock(&opp_table_lock);
> +
> + return opp_table;
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
> +
> +static void _opp_table_kref_release_unlocked(struct kref *kref)
> +{
> + struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
> struct opp_device *opp_dev;
>
> /* Release clk */

--
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