Re: [PATCH v6 05/10] cpufreq: mediatek: Add opp notification support

[Chen-Yu Tsai <wenst@chromium.org>]

On Fri, May 6, 2022 at 9:56 AM Rex-BC Chen <rex-bc.chen@mediatek.com> wrote:
>
> On Thu, 2022-05-05 at 19:52 +0800, Rex-BC Chen wrote:
> > From this opp notifier, cpufreq should listen to opp notification and
> > do
>
> Hello Viresh,
>
> There is still ">" in this patch...
> I think the root cause could be the "From" word in the beginning of
> this message.
> I will not use "From" in next version..

Could this be a bug in lore?

I'm not seeing this extra ">" in either the email in my inbox, viewed
raw, nor the patch downloaded from patchwork [1].


ChenYu

[1] https://patchwork.kernel.org/project/linux-mediatek/patch/20220505115226.20130-6-rex-bc.chen@mediatek.com/mbox/


>
> BRs,
> Rex
>
> > proper actions when receiving events of disable and voltage
> > adjustment.
> >
> > One of the user for this opp notifier is MediaTek SVS.
> > The MediaTek Smart Voltage Scaling (SVS) is a hardware which
> > calculates
> > suitable SVS bank voltages to OPP voltage table.
> >
> > Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
> > Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
> > Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@collabora.com>
> > ---
> >  drivers/cpufreq/mediatek-cpufreq.c | 91 +++++++++++++++++++++++++++-
> > --
> >  1 file changed, 83 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/cpufreq/mediatek-cpufreq.c
> > b/drivers/cpufreq/mediatek-cpufreq.c
> > index fe205eca657d..06d80ee06bbf 100644
> > --- a/drivers/cpufreq/mediatek-cpufreq.c
> > +++ b/drivers/cpufreq/mediatek-cpufreq.c
> > @@ -46,6 +46,11 @@ struct mtk_cpu_dvfs_info {
> >       int intermediate_voltage;
> >       bool need_voltage_tracking;
> >       int pre_vproc;
> > +     /* Avoid race condition for regulators between notify and
> > policy */
> > +     struct mutex reg_lock;
> > +     struct notifier_block opp_nb;
> > +     unsigned int opp_cpu;
> > +     unsigned long opp_freq;
> >       const struct mtk_cpufreq_platform_data *soc_data;
> >       int vtrack_max;
> >  };
> > @@ -182,6 +187,8 @@ static int mtk_cpufreq_set_target(struct
> > cpufreq_policy *policy,
> >
> >       pre_freq_hz = clk_get_rate(cpu_clk);
> >
> > +     mutex_lock(&info->reg_lock);
> > +
> >       if (unlikely(info->pre_vproc <= 0))
> >               pre_vproc = regulator_get_voltage(info->proc_reg);
> >       else
> > @@ -214,7 +221,7 @@ static int mtk_cpufreq_set_target(struct
> > cpufreq_policy *policy,
> >                       dev_err(cpu_dev,
> >                               "cpu%d: failed to scale up voltage!\n",
> > policy->cpu);
> >                       mtk_cpufreq_set_voltage(info, pre_vproc);
> > -                     return ret;
> > +                     goto out;
> >               }
> >       }
> >
> > @@ -224,8 +231,7 @@ static int mtk_cpufreq_set_target(struct
> > cpufreq_policy *policy,
> >               dev_err(cpu_dev,
> >                       "cpu%d: failed to re-parent cpu clock!\n",
> > policy->cpu);
> >               mtk_cpufreq_set_voltage(info, pre_vproc);
> > -             WARN_ON(1);
> > -             return ret;
> > +             goto out;
> >       }
> >
> >       /* Set the original PLL to target rate. */
> > @@ -235,7 +241,7 @@ static int mtk_cpufreq_set_target(struct
> > cpufreq_policy *policy,
> >                       "cpu%d: failed to scale cpu clock rate!\n",
> > policy->cpu);
> >               clk_set_parent(cpu_clk, armpll);
> >               mtk_cpufreq_set_voltage(info, pre_vproc);
> > -             return ret;
> > +             goto out;
> >       }
> >
> >       /* Set parent of CPU clock back to the original PLL. */
> > @@ -244,8 +250,7 @@ static int mtk_cpufreq_set_target(struct
> > cpufreq_policy *policy,
> >               dev_err(cpu_dev,
> >                       "cpu%d: failed to re-parent cpu clock!\n",
> > policy->cpu);
> >               mtk_cpufreq_set_voltage(info, inter_vproc);
> > -             WARN_ON(1);
> > -             return ret;
> > +             goto out;
> >       }
> >
> >       /*
> > @@ -260,15 +265,72 @@ static int mtk_cpufreq_set_target(struct
> > cpufreq_policy *policy,
> >                       clk_set_parent(cpu_clk, info->inter_clk);
> >                       clk_set_rate(armpll, pre_freq_hz);
> >                       clk_set_parent(cpu_clk, armpll);
> > -                     return ret;
> > +                     goto out;
> >               }
> >       }
> >
> > -     return 0;
> > +     info->opp_freq = freq_hz;
> > +
> > +out:
> > +     mutex_unlock(&info->reg_lock);
> > +
> > +     return ret;
> >  }
> >
> >  #define DYNAMIC_POWER "dynamic-power-coefficient"
> >
> > +static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
> > +                                 unsigned long event, void *data)
> > +{
> > +     struct dev_pm_opp *opp = data;
> > +     struct dev_pm_opp *new_opp;
> > +     struct mtk_cpu_dvfs_info *info;
> > +     unsigned long freq, volt;
> > +     struct cpufreq_policy *policy;
> > +     int ret = 0;
> > +
> > +     info = container_of(nb, struct mtk_cpu_dvfs_info, opp_nb);
> > +
> > +     if (event == OPP_EVENT_ADJUST_VOLTAGE) {
> > +             freq = dev_pm_opp_get_freq(opp);
> > +
> > +             mutex_lock(&info->reg_lock);
> > +             if (info->opp_freq == freq) {
> > +                     volt = dev_pm_opp_get_voltage(opp);
> > +                     ret = mtk_cpufreq_set_voltage(info, volt);
> > +                     if (ret)
> > +                             dev_err(info->cpu_dev,
> > +                                     "failed to scale voltage:
> > %d\n", ret);
> > +             }
> > +             mutex_unlock(&info->reg_lock);
> > +     } else if (event == OPP_EVENT_DISABLE) {
> > +             freq = dev_pm_opp_get_freq(opp);
> > +
> > +             /* case of current opp item is disabled */
> > +             if (info->opp_freq == freq) {
> > +                     freq = 1;
> > +                     new_opp = dev_pm_opp_find_freq_ceil(info-
> > >cpu_dev,
> > +                                                         &freq);
> > +                     if (IS_ERR(new_opp)) {
> > +                             dev_err(info->cpu_dev,
> > +                                     "all opp items are
> > disabled\n");
> > +                             ret = PTR_ERR(new_opp);
> > +                             return notifier_from_errno(ret);
> > +                     }
> > +
> > +                     dev_pm_opp_put(new_opp);
> > +                     policy = cpufreq_cpu_get(info->opp_cpu);
> > +                     if (policy) {
> > +                             cpufreq_driver_target(policy, freq /
> > 1000,
> > +                                                   CPUFREQ_RELATION_
> > L);
> > +                             cpufreq_cpu_put(policy);
> > +                     }
> > +             }
> > +     }
> > +
> > +     return notifier_from_errno(ret);
> > +}
> > +
> >  static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info,
> > int cpu)
> >  {
> >       struct device *cpu_dev;
> > @@ -357,6 +419,18 @@ static int mtk_cpu_dvfs_info_init(struct
> > mtk_cpu_dvfs_info *info, int cpu)
> >       info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
> >       dev_pm_opp_put(opp);
> >
> > +     mutex_init(&info->reg_lock);
> > +
> > +     info->opp_cpu = cpu;
> > +     info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
> > +     ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
> > +     if (ret) {
> > +             dev_err(cpu_dev, "cpu%d: failed to register opp
> > notifier\n", cpu);
> > +             goto out_disable_inter_clock;
> > +     }
> > +
> > +     info->opp_freq = clk_get_rate(info->cpu_clk);
> > +
> >       /*
> >        * If SRAM regulator is present, software "voltage tracking" is
> > needed
> >        * for this CPU power domain.
> > @@ -421,6 +495,7 @@ static void mtk_cpu_dvfs_info_release(struct
> > mtk_cpu_dvfs_info *info)
> >       }
> >
> >       dev_pm_opp_of_cpumask_remove_table(&info->cpus);
> > +     dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
> >  }
> >
> >  static int mtk_cpufreq_init(struct cpufreq_policy *policy)
>
>
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