linux-kernel - Re: [PATCH v4 1/5] devfreq: exynos-bus: correct clock enable sequence

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Date:   Thu, 25 Jul 2019 23:59:21 +0900
From:   Chanwoo Choi <cwchoi00@...il.com>
To:     Kamil Konieczny <k.konieczny@...tner.samsung.com>
Cc:     Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Kukjin Kim <kgene@...nel.org>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Mark Rutland <mark.rutland@....com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Nishanth Menon <nm@...com>, Rob Herring <robh+dt@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Viresh Kumar <vireshk@...nel.org>,
        devicetree <devicetree@...r.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Linux PM list <linux-pm@...r.kernel.org>,
        linux-samsung-soc <linux-samsung-soc@...r.kernel.org>
Subject: Re: [PATCH v4 1/5] devfreq: exynos-bus: correct clock enable sequence

Hi,

You are missing my Acked tag.

2019년 7월 25일 (목) 오후 11:44, <k.konieczny@...tner.samsung.com>님이 작성:
>
> Regulators should be enabled before clocks to avoid h/w hang. This
> require change in exynos_bus_probe() to move exynos_bus_parse_of()
> after exynos_bus_parent_parse_of() and change in error handling.
> Similar change is needed in exynos_bus_exit() where clock should be
> disabled before regulators.
>
> Signed-off-by: Kamil Konieczny <k.konieczny@...tner.samsung.com>
> ---
> Changes:
> v4:
> - move regulator disable after clock disable
> - remove unrelated changes
> - add disabling regulators in error path in exynos_bus_probe()
>
> ---
>  drivers/devfreq/exynos-bus.c | 31 +++++++++++++++++--------------
>  1 file changed, 17 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> index 486cc5b422f1..f34fa26f00d0 100644
> --- a/drivers/devfreq/exynos-bus.c
> +++ b/drivers/devfreq/exynos-bus.c
> @@ -194,11 +194,10 @@ static void exynos_bus_exit(struct device *dev)
>         if (ret < 0)
>                 dev_warn(dev, "failed to disable the devfreq-event devices\n");
>
> -       if (bus->regulator)
> -               regulator_disable(bus->regulator);
> -
>         dev_pm_opp_of_remove_table(dev);
>         clk_disable_unprepare(bus->clk);
> +       if (bus->regulator)
> +               regulator_disable(bus->regulator);
>  }
>
>  /*
> @@ -386,6 +385,7 @@ static int exynos_bus_probe(struct platform_device *pdev)
>         struct exynos_bus *bus;
>         int ret, max_state;
>         unsigned long min_freq, max_freq;
> +       bool passive = false;
>
>         if (!np) {
>                 dev_err(dev, "failed to find devicetree node\n");
> @@ -399,27 +399,27 @@ static int exynos_bus_probe(struct platform_device *pdev)
>         bus->dev = &pdev->dev;
>         platform_set_drvdata(pdev, bus);
>
> -       /* Parse the device-tree to get the resource information */
> -       ret = exynos_bus_parse_of(np, bus);
> -       if (ret < 0)
> -               return ret;
> -
>         profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
> -       if (!profile) {
> -               ret = -ENOMEM;
> -               goto err;
> -       }
> +       if (!profile)
> +               return -ENOMEM;
>
>         node = of_parse_phandle(dev->of_node, "devfreq", 0);
>         if (node) {
>                 of_node_put(node);
> -               goto passive;
> +               passive = true;
>         } else {
>                 ret = exynos_bus_parent_parse_of(np, bus);
> +               if (ret < 0)
> +                       return ret;
>         }
>
> +       /* Parse the device-tree to get the resource information */
> +       ret = exynos_bus_parse_of(np, bus);
>         if (ret < 0)
> -               goto err;
> +               goto err_reg;
> +
> +       if (passive)
> +               goto passive;
>
>         /* Initialize the struct profile and governor data for parent device */
>         profile->polling_ms = 50;
> @@ -510,6 +510,9 @@ static int exynos_bus_probe(struct platform_device *pdev)
>  err:
>         dev_pm_opp_of_remove_table(dev);
>         clk_disable_unprepare(bus->clk);
> +err_reg:
> +       if (!passive)
> +               regulator_disable(bus->regulator);
>
>         return ret;
>  }
> --
> 2.22.0
>


-- 
Best Regards,
Chanwoo Choi