Re: [PATCH V3 08/10] OPP: Configure all required OPPs

[Ulf Hansson]

On 25 October 2018 at 07:52, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> Now that all the infrastructure is in place to support multiple required
> OPPs, lets switch over to using it.
>
> A new internal routine _set_required_opps() takes care of updating
> performance state for all the required OPPs. With this the performance
> state updates are supported even when the end device needs to configure
> regulators as well, that wasn't the case earlier.
>
> The pstates were earlier stored in the end device's OPP structures, that
> also changes now as those values are stored in the genpd's OPP
> structures. And so we switch over to using
> pm_genpd_opp_to_performance_state() instead of
> of_genpd_opp_to_performance_state() to get performance state for the
> genpd OPPs.
>
> The routine _generic_set_opp_domain() is not required anymore and is
> removed.
>
> On errors we don't try to recover by reverting to old settings as things
> are really complex now and the calls here should never really fail
> unless there is a bug. There is no point increasing the complexity, for
> code which will never be executed.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

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

Kind regards
Uffe

> ---
>  drivers/opp/core.c | 113 ++++++++++++++++++++++++++-------------------
>  drivers/opp/of.c   |   5 +-
>  2 files changed, 68 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index cef2ccda355d..0eaa954b3f6c 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -548,44 +548,6 @@ _generic_set_opp_clk_only(struct device *dev, struct clk *clk,
>         return ret;
>  }
>
> -static inline int
> -_generic_set_opp_domain(struct device *dev, struct clk *clk,
> -                       unsigned long old_freq, unsigned long freq,
> -                       unsigned int old_pstate, unsigned int new_pstate)
> -{
> -       int ret;
> -
> -       /* Scaling up? Scale domain performance state before frequency */
> -       if (freq > old_freq) {
> -               ret = dev_pm_genpd_set_performance_state(dev, new_pstate);
> -               if (ret)
> -                       return ret;
> -       }
> -
> -       ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
> -       if (ret)
> -               goto restore_domain_state;
> -
> -       /* Scaling down? Scale domain performance state after frequency */
> -       if (freq < old_freq) {
> -               ret = dev_pm_genpd_set_performance_state(dev, new_pstate);
> -               if (ret)
> -                       goto restore_freq;
> -       }
> -
> -       return 0;
> -
> -restore_freq:
> -       if (_generic_set_opp_clk_only(dev, clk, freq, old_freq))
> -               dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
> -                       __func__, old_freq);
> -restore_domain_state:
> -       if (freq > old_freq)
> -               dev_pm_genpd_set_performance_state(dev, old_pstate);
> -
> -       return ret;
> -}
> -
>  static int _generic_set_opp_regulator(const struct opp_table *opp_table,
>                                       struct device *dev,
>                                       unsigned long old_freq,
> @@ -663,6 +625,56 @@ static int _set_opp_custom(const struct opp_table *opp_table,
>         return opp_table->set_opp(data);
>  }
>
> +/* This is only called for PM domain for now */
> +static int _set_required_opps(struct device *dev,
> +                             struct opp_table *opp_table,
> +                             struct dev_pm_opp *opp)
> +{
> +       struct opp_table **required_opp_tables = opp_table->required_opp_tables;
> +       struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
> +       unsigned int pstate;
> +       int i, ret = 0;
> +
> +       if (!required_opp_tables)
> +               return 0;
> +
> +       /* Single genpd case */
> +       if (!genpd_virt_devs) {
> +               pstate = opp->required_opps[0]->pstate;
> +               ret = dev_pm_genpd_set_performance_state(dev, pstate);
> +               if (ret) {
> +                       dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
> +                               dev_name(dev), pstate, ret);
> +               }
> +               return ret;
> +       }
> +
> +       /* Multiple genpd case */
> +
> +       /*
> +        * Acquire genpd_virt_dev_lock to make sure we don't use a genpd_dev
> +        * after it is freed from another thread.
> +        */
> +       mutex_lock(&opp_table->genpd_virt_dev_lock);
> +
> +       for (i = 0; i < opp_table->required_opp_count; i++) {
> +               pstate = opp->required_opps[i]->pstate;
> +
> +               if (!genpd_virt_devs[i])
> +                       continue;
> +
> +               ret = dev_pm_genpd_set_performance_state(genpd_virt_devs[i], pstate);
> +               if (ret) {
> +                       dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
> +                               dev_name(genpd_virt_devs[i]), pstate, ret);
> +                       break;
> +               }
> +       }
> +       mutex_unlock(&opp_table->genpd_virt_dev_lock);
> +
> +       return ret;
> +}
> +
>  /**
>   * dev_pm_opp_set_rate() - Configure new OPP based on frequency
>   * @dev:        device for which we do this operation
> @@ -730,6 +742,13 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
>         dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
>                 old_freq, freq);
>
> +       /* Scaling up? Configure required OPPs before frequency */
> +       if (freq > old_freq) {
> +               ret = _set_required_opps(dev, opp_table, opp);
> +               if (ret)
> +                       goto put_opp;
> +       }
> +
>         if (opp_table->set_opp) {
>                 ret = _set_opp_custom(opp_table, dev, old_freq, freq,
>                                       IS_ERR(old_opp) ? NULL : old_opp->supplies,
> @@ -740,19 +759,17 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
>                                                  opp->supplies);
>         } else {
>                 /* Only frequency scaling */
> +               ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
> +       }
>
> -               /*
> -                * We don't support devices with both regulator and
> -                * domain performance-state for now.
> -                */
> -               if (opp_table->genpd_performance_state)
> -                       ret = _generic_set_opp_domain(dev, clk, old_freq, freq,
> -                                                     IS_ERR(old_opp) ? 0 : old_opp->pstate,
> -                                                     opp->pstate);
> -               else
> -                       ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
> +       /* Scaling down? Configure required OPPs after frequency */
> +       if (!ret && freq < old_freq) {
> +               ret = _set_required_opps(dev, opp_table, opp);
> +               if (ret)
> +                       dev_err(dev, "Failed to set required opps: %d\n", ret);
>         }
>
> +put_opp:
>         dev_pm_opp_put(opp);
>  put_old_opp:
>         if (!IS_ERR(old_opp))
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index 71aef28953c2..4e494720ac25 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -595,12 +595,13 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
>         if (!of_property_read_u32(np, "clock-latency-ns", &val))
>                 new_opp->clock_latency_ns = val;
>
> -       new_opp->pstate = of_genpd_opp_to_performance_state(dev, np);
> -
>         ret = opp_parse_supplies(new_opp, dev, opp_table);
>         if (ret)
>                 goto free_required_opps;
>
> +       if (opp_table->is_genpd)
> +               new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
> +
>         ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
>         if (ret) {
>                 /* Don't return error for duplicate OPPs */
> --
> 2.19.1.568.g152ad8e3369a
>