From: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
To: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cc: Thierry Reding
<thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
"Rafael J . Wysocki"
<rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org>,
linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 1/2] cpufreq: tegra186: Fix initial frequency
Date: Mon, 13 Jul 2020 08:55:54 +0530 [thread overview]
Message-ID: <20200713032554.cykywnygxln6ukrl@vireshk-i7> (raw)
In-Reply-To: <20200712100645.13927-1-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
On 12-07-20, 11:06, 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
>
> Although we could fix this by adding a 'get' operator for the Tegra186
> CPUFREQ driver, there is really little point because the CPUFREQ on
> Tegra186 is set by writing a value stored in the frequency table to a
> register and we just need to set the initial frequency.
The hardware still runs at the frequency requested by cpufreq core here, right ?
It is better to provide the get() callback as it is also used to show the
current frequency in userspace.
> So for Tegra186
> the simplest way to fix this is read the register that sets the
> frequency for each CPU and set the initial frequency when initialising
> the CPUFREQ driver.
>
> Signed-off-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---
> drivers/cpufreq/tegra186-cpufreq.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/cpufreq/tegra186-cpufreq.c b/drivers/cpufreq/tegra186-cpufreq.c
> index 3d2f143748ef..c44190ce3f03 100644
> --- a/drivers/cpufreq/tegra186-cpufreq.c
> +++ b/drivers/cpufreq/tegra186-cpufreq.c
> @@ -59,6 +59,7 @@ static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
> struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
> const struct tegra186_cpufreq_cluster_info *info =
> cluster->info;
> + u32 edvd_val;
> int core;
>
> for (core = 0; core < ARRAY_SIZE(info->cpus); core++) {
> @@ -71,6 +72,13 @@ static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
> policy->driver_data =
> data->regs + info->offset + EDVD_CORE_VOLT_FREQ(core);
> policy->freq_table = cluster->table;
> +
> + edvd_val = readl(policy->driver_data);
> +
> + for (i = 0; cluster->table[i].frequency != CPUFREQ_TABLE_END; i++) {
> + if (cluster->table[i].driver_data == edvd_val)
> + policy->cur = cluster->table[i].frequency;
> + }
> break;
> }
>
> --
> 2.17.1
--
viresh
next prev parent reply other threads:[~2020-07-13 3:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-12 10:06 [PATCH 1/2] cpufreq: tegra186: Fix initial frequency Jon Hunter
[not found] ` <20200712100645.13927-1-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-12 10:06 ` [PATCH 2/2] cpufreq: tegra186: Simplify probe return path Jon Hunter
[not found] ` <20200712100645.13927-2-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-13 3:28 ` Viresh Kumar
2020-07-13 3:25 ` Viresh Kumar [this message]
2020-07-13 16:37 ` [PATCH 1/2] cpufreq: tegra186: Fix initial frequency Jon Hunter
[not found] ` <3d6091f2-6b04-185f-6c23-e39a34b87877-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-14 3:46 ` Viresh Kumar
2020-07-14 7:26 ` Jon Hunter
[not found] ` <aa941c67-1dec-5363-7bd7-5e9d8d324110-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-14 7:31 ` Viresh Kumar
2020-07-31 12:14 ` Jon Hunter
2020-08-04 5:25 ` Viresh Kumar
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