linux-kernel - Re: [PATCH 2/5] thermal: exynos: cleanup of clk err check for exynos_tmu

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Date:   Tue, 17 Jul 2018 14:24:24 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Anand Moon <linux.amoon@...il.com>
Cc:     Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Zhang Rui <rui.zhang@...el.com>,
        Eduardo Valentin <edubezval@...il.com>,
        Kukjin Kim <kgene@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>, linux-pm@...r.kernel.org,
        "linux-samsung-soc@...r.kernel.org" 
        <linux-samsung-soc@...r.kernel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org
Subject: Re: [PATCH 2/5] thermal: exynos: cleanup of clk err check for exynos_tmu_work

On 17 July 2018 at 12:12, Anand Moon <linux.amoon@...il.com> wrote:
> cleanup err check in exynos_tmu_work as clk internal
> framework will perform if clk is enable/disable
> so drop the double check of IS_ERR and other such references.

I do not understand the statement. Clock framework will perform if clk
is enable/disable? How clock can be "enable" or "disable"? You mean
gate clock? you mean clock pointer is an ERR pointer?

> CC: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
> Signed-off-by: Anand Moon <linux.amoon@...il.com>
> ---
>  drivers/thermal/samsung/exynos_tmu.c | 19 ++++++-------------
>  1 file changed, 6 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
> index 0164c9e..2dbde97 100644
> --- a/drivers/thermal/samsung/exynos_tmu.c
> +++ b/drivers/thermal/samsung/exynos_tmu.c
> @@ -300,8 +300,7 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
>
>         mutex_lock(&data->lock);
>         clk_enable(data->clk);
> -       if (!IS_ERR(data->clk_sec))
> -               clk_enable(data->clk_sec);
> +       clk_enable(data->clk_sec);
>
>         status = readb(data->base + EXYNOS_TMU_REG_STATUS);
>         if (!status) {
> @@ -334,8 +333,7 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
>  err:
>         clk_disable(data->clk);
>         mutex_unlock(&data->lock);
> -       if (!IS_ERR(data->clk_sec))
> -               clk_disable(data->clk_sec);
> +       clk_disable(data->clk_sec);
>  out:
>         return ret;
>  }
> @@ -789,19 +787,16 @@ static void exynos_tmu_work(struct work_struct *work)
>         struct exynos_tmu_data *data = container_of(work,
>                         struct exynos_tmu_data, irq_work);
>
> -       if (!IS_ERR(data->clk_sec))
> -               clk_enable(data->clk_sec);
> -       if (!IS_ERR(data->clk_sec))
> -               clk_disable(data->clk_sec);
> -
>         thermal_zone_device_update(data->tzd, THERMAL_EVENT_UNSPECIFIED);
>
>         mutex_lock(&data->lock);
>         clk_enable(data->clk);
> +       clk_enable(data->clk_sec);

You are changing here the logic completely. Before the "enable" was
followed immediately by "disable". Now you are moving disable
somewhere else... All this looks suspicious...

Best regards,
Krzysztof

>
>         /* TODO: take action based on particular interrupt */
>         data->tmu_clear_irqs(data);
>
> +       clk_disable(data->clk_sec);
>         clk_disable(data->clk);
>         mutex_unlock(&data->lock);
>         enable_irq(data->irq);
> @@ -1134,8 +1129,7 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>  err_sclk:
>         clk_disable_unprepare(data->sclk);
>  err_clk_sec:
> -       if (!IS_ERR(data->clk_sec))
> -               clk_disable_unprepare(data->clk_sec);
> +       clk_disable_unprepare(data->clk_sec);
>  err_clk:
>         clk_disable_unprepare(data->clk);
>  err_sensor:
> @@ -1155,8 +1149,7 @@ static int exynos_tmu_remove(struct platform_device *pdev)
>
>         clk_disable_unprepare(data->sclk);
>         clk_disable_unprepare(data->clk);
> -       if (!IS_ERR(data->clk_sec))
> -               clk_disable_unprepare(data->clk_sec);
> +       clk_disable_unprepare(data->clk_sec);
>
>         if (!IS_ERR(data->regulator))
>                 regulator_disable(data->regulator);
> --
> 2.7.4
>