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Message-ID: <20220506041518.5j5rfakayur64y7e@vireshk-i7>
Date: Fri, 6 May 2022 09:45:18 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Rex-BC Chen <rex-bc.chen@...iatek.com>
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 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.
--
viresh
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