linux-kernel - Re: [PATCH v1] cpufreq: tegra20: Fix imbalanced clock enable count

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Message-ID: <20180523055817.subrv6oeckfecpcp@vireshk-i7>
Date:   Wed, 23 May 2018 11:28:17 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        linux-tegra@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] cpufreq: tegra20: Fix imbalanced clock enable count

On 23-05-18, 00:14, Dmitry Osipenko wrote:
> Tegra20-cpufreq driver missed enabling the CPU clocks. This results in a
> clock-enable refcount disbalance on PLL_P <-> PLL_X reparent, causing
> PLL_X to get disabled while it shouldn't. Fix this by enabling the clocks
> on the driver probe.
> 
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
> 
> CPUFreq maintainers,
> 
> Please take into account that this patch is made on top of my recent
> series of patches [0] "Clean up Tegra20 cpufreq driver" that was fully
> reviewed, but seems not applied yet. Let me know if you prefer to re-spin
> the [0], including this patch into the series.
> 
> [0] https://patchwork.ozlabs.org/project/linux-tegra/list/?series=45321

This is already picked by Rafael and is sitting in pm/bleeding-edge
branch. Should get merged into linux-next in a day or two.

>  drivers/cpufreq/tegra20-cpufreq.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
> index 05f57dcd5215..ca5229265b60 100644
> --- a/drivers/cpufreq/tegra20-cpufreq.c
> +++ b/drivers/cpufreq/tegra20-cpufreq.c
> @@ -176,6 +176,14 @@ static int tegra20_cpufreq_probe(struct platform_device *pdev)
>  		goto put_pll_x;
>  	}
>  
> +	err = clk_prepare_enable(cpufreq->pll_x_clk);
> +	if (err)
> +		goto put_pll_p;
> +
> +	err = clk_prepare_enable(cpufreq->pll_p_clk);
> +	if (err)
> +		goto disable_pll_x;
> +
>  	cpufreq->dev = &pdev->dev;
>  	cpufreq->driver.get = cpufreq_generic_get;
>  	cpufreq->driver.attr = cpufreq_generic_attr;
> @@ -192,12 +200,16 @@ static int tegra20_cpufreq_probe(struct platform_device *pdev)
>  
>  	err = cpufreq_register_driver(&cpufreq->driver);
>  	if (err)
> -		goto put_pll_p;
> +		goto disable_pll_p;
>  
>  	platform_set_drvdata(pdev, cpufreq);
>  
>  	return 0;
>  
> +disable_pll_p:
> +	clk_disable_unprepare(cpufreq->pll_p_clk);
> +disable_pll_x:
> +	clk_disable_unprepare(cpufreq->pll_x_clk);
>  put_pll_p:
>  	clk_put(cpufreq->pll_p_clk);
>  put_pll_x:
> @@ -214,6 +226,8 @@ static int tegra20_cpufreq_remove(struct platform_device *pdev)
>  
>  	cpufreq_unregister_driver(&cpufreq->driver);
>  
> +	clk_disable_unprepare(cpufreq->pll_p_clk);
> +	clk_disable_unprepare(cpufreq->pll_x_clk);
>  	clk_put(cpufreq->pll_p_clk);
>  	clk_put(cpufreq->pll_x_clk);
>  	clk_put(cpufreq->cpu_clk);

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh