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

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Message-ID: <24066927.6Emhk5qWAg@senjougahara>
Date: Wed, 27 Aug 2025 11:09:23 +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 2/2] cpufreq: tegra186: Initialize all cores to base frequencies

On Wednesday, August 27, 2025 5:16 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 base
> 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 | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/tegra186-cpufreq.c
> b/drivers/cpufreq/tegra186-cpufreq.c index
> 6c394b429b6182faffabf222e5af501393dbbba9..ef288705f00b0918d0f8963ef9cc9fc53
> be88091 100644 --- a/drivers/cpufreq/tegra186-cpufreq.c
> +++ b/drivers/cpufreq/tegra186-cpufreq.c
> @@ -229,7 +229,8 @@ 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;
> +	u32 edvd_val, cpu;
> 
>  	data = devm_kzalloc(&pdev->dev,
>  			    struct_size(data, clusters, 
TEGRA186_NUM_CLUSTERS),
> @@ -257,6 +258,14 @@ static int tegra186_cpufreq_probe(struct
> platform_device *pdev) 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[0].driver_data;
> +				edvd_offset = data->cpus[cpu].edvd_offset;
> +				writel(edvd_val, data->regs + 
edvd_offset);
> +			}
> +		}
>  	}
> 
>  	tegra186_cpufreq_driver.driver_data = data;

Looks OK, but I think it might be better to set the frequency to Fmax instead 
of Fmin to avoid any slowdown during boot.

Cheers,
Mikko