linux-kernel - Re: [PATCH V2] cpufreq: tegra186: Fix initial frequency

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Message-ID: <20200825055003.qfsuktsv7cyouxei@vireshk-i7>
Date:   Tue, 25 Aug 2020 11:20:03 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Jon Hunter <jonathanh@...dia.com>
Cc:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Thierry Reding <thierry.reding@...il.com>,
        linux-pm@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2] cpufreq: tegra186: Fix initial frequency

On 24-08-20, 15:59, Jon Hunter wrote:
> Commit 6cc3d0e9a097 ("cpufreq: tegra186: add
> CPUFREQ_NEED_INITIAL_FREQ_CHECK flag") fixed CPUFREQ support for
> Tegra186 but as a consequence the following warnings are now seen on
> boot ...
> 
>  cpufreq: cpufreq_online: CPU0: Running at unlisted freq: 0 KHz
>  cpufreq: cpufreq_online: CPU0: Unlisted initial frequency changed to: 2035200 KHz
>  cpufreq: cpufreq_online: CPU1: Running at unlisted freq: 0 KHz
>  cpufreq: cpufreq_online: CPU1: Unlisted initial frequency changed to: 2035200 KHz
>  cpufreq: cpufreq_online: CPU2: Running at unlisted freq: 0 KHz
>  cpufreq: cpufreq_online: CPU2: Unlisted initial frequency changed to: 2035200 KHz
>  cpufreq: cpufreq_online: CPU3: Running at unlisted freq: 0 KHz
>  cpufreq: cpufreq_online: CPU3: Unlisted initial frequency changed to: 2035200 KHz
>  cpufreq: cpufreq_online: CPU4: Running at unlisted freq: 0 KHz
>  cpufreq: cpufreq_online: CPU4: Unlisted initial frequency changed to: 2035200 KHz
>  cpufreq: cpufreq_online: CPU5: Running at unlisted freq: 0 KHz
>  cpufreq: cpufreq_online: CPU5: Unlisted initial frequency changed to: 2035200 KHz
> 
> Fix this by adding a 'get' callback for the Tegra186 CPUFREQ driver to
> retrieve the current operating frequency for a given CPU. The 'get'
> callback uses the current 'ndiv' value that is programmed to determine
> that current operating frequency.
> 
> Signed-off-by: Jon Hunter <jonathanh@...dia.com>
> ---
> Changes since V1:
> - Moved code into a 'get' callback
> 
>  drivers/cpufreq/tegra186-cpufreq.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/drivers/cpufreq/tegra186-cpufreq.c b/drivers/cpufreq/tegra186-cpufreq.c
> index 01e1f58ba422..0d0fcff60765 100644
> --- a/drivers/cpufreq/tegra186-cpufreq.c
> +++ b/drivers/cpufreq/tegra186-cpufreq.c
> @@ -14,6 +14,7 @@
>  
>  #define EDVD_CORE_VOLT_FREQ(core)		(0x20 + (core) * 0x4)
>  #define EDVD_CORE_VOLT_FREQ_F_SHIFT		0
> +#define EDVD_CORE_VOLT_FREQ_F_MASK		0xffff
>  #define EDVD_CORE_VOLT_FREQ_V_SHIFT		16
>  
>  struct tegra186_cpufreq_cluster_info {
> @@ -91,10 +92,39 @@ static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
>  	return 0;
>  }
>  
> +static unsigned int tegra186_cpufreq_get(unsigned int cpu)
> +{
> +	struct cpufreq_frequency_table *tbl;
> +	struct cpufreq_policy *policy;
> +	void __iomem *edvd_reg;
> +	unsigned int i, freq = 0;
> +	u32 ndiv;
> +
> +	policy = cpufreq_cpu_get(cpu);
> +	if (!policy)
> +		return -EINVAL;

This should be return 0;

Applied with that change. Thanks.

-- 
viresh