linux-kernel - Re: [PATCH v2 2/2] cpufreq: tegra186: Initialize all cores to max frequencies

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Message-ID: <2606828.Sgy9Pd6rRy@senjougahara>
Date: Fri, 29 Aug 2025 09:18:22 +0900
From: Mikko Perttunen <mperttunen@...dia.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>,
 Viresh Kumar <viresh.kumar@...aro.org>,
 Thierry Reding <thierry.reding@...il.com>,
 Jonathan Hunter <jonathanh@...dia.com>, Aaron Kling <luceoscutum@...il.com>,
 Sumit Gupta <sumitg@...dia.com>, webgeek1234@...il.com
Cc: Thierry Reding <treding@...dia.com>, linux-pm@...r.kernel.org,
 linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
 Aaron Kling <webgeek1234@...il.com>
Subject:
 Re: [PATCH v2 2/2] cpufreq: tegra186: Initialize all cores to max frequencies

On Friday, August 29, 2025 1:57 AM Aaron Kling via B4 Relay wrote:
> From: Aaron Kling <webgeek1234@...il.com>
> 
> During initialization, the EDVD_COREx_VOLT_FREQ registers for some cores
> are still at reset values and not reflecting the actual frequency. This
> causes get calls to fail. Set all cores to their respective max
> frequency during probe to initialize the registers to working values.
> 
> Suggested-by: Mikko Perttunen <mperttunen@...dia.com>
> Signed-off-by: Aaron Kling <webgeek1234@...il.com>
> ---
>  drivers/cpufreq/tegra186-cpufreq.c | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/cpufreq/tegra186-cpufreq.c
> b/drivers/cpufreq/tegra186-cpufreq.c index
> 6c394b429b6182faffabf222e5af501393dbbba9..3cd42db955c1c705f9774879e34b71ae1
> 24e86d2 100644 --- a/drivers/cpufreq/tegra186-cpufreq.c
> +++ b/drivers/cpufreq/tegra186-cpufreq.c
> @@ -138,7 +138,8 @@ static struct cpufreq_driver tegra186_cpufreq_driver = {
> 
>  static struct cpufreq_frequency_table *init_vhint_table(
>  	struct platform_device *pdev, struct tegra_bpmp *bpmp,
> -	struct tegra186_cpufreq_cluster *cluster, unsigned int cluster_id)
> +	struct tegra186_cpufreq_cluster *cluster, unsigned int cluster_id,
> +	int *max_rate)

'max_rate' sounds like it's the rate itself and not the index. Perhaps have 
init_vhint_table output num_rates and calculate in probe? We should also 
handle the possibility of num_rates being 0. Otherwise looks good to me.

Thanks!
Mikko

>  {
>  	struct cpufreq_frequency_table *table;
>  	struct mrq_cpu_vhint_request req;
> @@ -218,6 +219,7 @@ static struct cpufreq_frequency_table *init_vhint_table(
> }
> 
>  	table[j].frequency = CPUFREQ_TABLE_END;
> +	*max_rate = num_rates - 1;
> 
>  free:
>  	dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
> @@ -229,7 +231,9 @@ static int tegra186_cpufreq_probe(struct platform_device
> *pdev) {
>  	struct tegra186_cpufreq_data *data;
>  	struct tegra_bpmp *bpmp;
> -	unsigned int i = 0, err;
> +	unsigned int i = 0, err, edvd_offset;
> +	int max_rate = 0;
> +	u32 edvd_val, cpu;
> 
>  	data = devm_kzalloc(&pdev->dev,
>  			    struct_size(data, clusters, 
TEGRA186_NUM_CLUSTERS),
> @@ -252,11 +256,19 @@ static int tegra186_cpufreq_probe(struct
> platform_device *pdev) for (i = 0; i < TEGRA186_NUM_CLUSTERS; i++) {
>  		struct tegra186_cpufreq_cluster *cluster = &data-
>clusters[i];
> 
> -		cluster->table = init_vhint_table(pdev, bpmp, cluster, i);
> +		cluster->table = init_vhint_table(pdev, bpmp, cluster, i, 
&max_rate);
>  		if (IS_ERR(cluster->table)) {
>  			err = PTR_ERR(cluster->table);
>  			goto put_bpmp;
>  		}
> +
> +		for (cpu = 0; cpu < ARRAY_SIZE(tegra186_cpus); cpu++) {
> +			if (data->cpus[cpu].bpmp_cluster_id == i) {
> +				edvd_val = cluster-
>table[max_rate].driver_data;
> +				edvd_offset = data->cpus[cpu].edvd_offset;
> +				writel(edvd_val, data->regs + 
edvd_offset);
> +			}
> +		}
>  	}
> 
>  	tegra186_cpufreq_driver.driver_data = data;