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Message-ID: <507cf3d3df72923f96e142a74e0ef5fe5b8171e1.camel@mediatek.com>
Date: Fri, 6 May 2022 14:21:31 +0800
From: Rex-BC Chen <rex-bc.chen@...iatek.com>
To: Viresh Kumar <viresh.kumar@...aro.org>
CC: <rafael@...nel.org>, <robh+dt@...nel.org>, <krzk+dt@...nel.org>,
<matthias.bgg@...il.com>, <jia-wei.chang@...iatek.com>,
<roger.lu@...iatek.com>, <hsinyi@...gle.com>,
<khilman@...libre.com>, <angelogioacchino.delregno@...labora.com>,
<linux-pm@...r.kernel.org>, <devicetree@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-mediatek@...ts.infradead.org>,
<Project_Global_Chrome_Upstream_Group@...iatek.com>,
"Andrew-sh . Cheng" <andrew-sh.cheng@...iatek.com>
Subject: Re: [PATCH v6 05/10] cpufreq: mediatek: Add opp notification support
On Fri, 2022-05-06 at 09:45 +0530, Viresh Kumar wrote:
> On 05-05-22, 19:52, Rex-BC Chen wrote:
> > > From this opp notifier, cpufreq should listen to opp notification
> > > and do
> >
> > 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@...iatek.com>
> > Signed-off-by: Jia-Wei Chang <jia-wei.chang@...iatek.com>
> > Signed-off-by: Rex-BC Chen <rex-bc.chen@...iatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@...labora.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;
>
> The name opp_freq doesn't fit well, I renamed it to current_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);
>
> This is a resource as well, which should have been initialized before
> registering notifier.
>
> Applied with above changes. Thanks.
>
Hello Viresh,
Thanks for your help!
BRs,
Rex
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