linux-kernel - Re: [PATCH V4 2/7] OPP: Improve _find_table_of_opp

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Message-ID: <CAPDyKFret-vV-jSMYtJD1JFDak6HB+xShn8ps0y337EhycGs5Q@mail.gmail.com>
Date:   Fri, 14 Dec 2018 11:40:36 +0100
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Rafael Wysocki <rjw@...ysocki.net>,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Niklas Cassel <niklas.cassel@...aro.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V4 2/7] OPP: Improve _find_table_of_opp_np()

On Fri, 14 Dec 2018 at 11:15, Viresh Kumar <viresh.kumar@...aro.org> wrote:
>
> Make _find_table_of_opp_np() more efficient by using of_get_parent() to
> find the parent OPP table node.
>
> Tested-by: Rajendra Nayak <rnayak@...eaurora.org>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>

Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>

Kind regards
Uffe


> ---
>  drivers/opp/of.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index 3ef7f38c0986..8e57d257be77 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -114,19 +114,25 @@ static struct device_node *of_parse_required_opp(struct device_node *np,
>  static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
>  {
>         struct opp_table *opp_table;
> -       struct dev_pm_opp *opp;
> +       struct device_node *opp_table_np;
>
>         lockdep_assert_held(&opp_table_lock);
>
> +       opp_table_np = of_get_parent(opp_np);
> +       if (!opp_table_np)
> +               goto err;
> +
> +       /* It is safe to put the node now as all we need now is its address */
> +       of_node_put(opp_table_np);
> +
>         list_for_each_entry(opp_table, &opp_tables, node) {
> -               opp = _find_opp_of_np(opp_table, opp_np);
> -               if (opp) {
> -                       dev_pm_opp_put(opp);
> +               if (opp_table_np == opp_table->np) {
>                         _get_opp_table_kref(opp_table);
>                         return opp_table;
>                 }
>         }
>
> +err:
>         return ERR_PTR(-ENODEV);
>  }
>
> --
> 2.19.1.568.g152ad8e3369a
>