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

From: Viresh Kumar
Date: Wed May 23 2018 - 01:04:41 EST


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@xxxxxxxxx>
> ---
>
> 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@xxxxxxxxxx>

--
viresh