Re: [PATCH] [v2] hwrng: exynos - Fix runtime PM imbalance on error

From: Lukasz Stelmach <l.stelmach@samsung.com>
To: Dinghao Liu <dinghao.liu@zju.edu.cn>
Cc: kjlu@umn.edu, Matt Mackall <mpm@selenic.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Kukjin Kim <kgene@kernel.org>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	linux-samsung-soc@vger.kernel.org, linux-crypto@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [PATCH] [v2] hwrng: exynos - Fix runtime PM imbalance on error
Date: Fri, 22 May 2020 11:07:11 +0200	[thread overview]
Message-ID: <dleftj1rncz6bk.fsf%l.stelmach@samsung.com> (raw)
In-Reply-To: <20200522011659.26727-1-dinghao.liu@zju.edu.cn> (Dinghao Liu's message of "Fri, 22 May 2020 09:16:59 +0800")

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It was <2020-05-22 pią 09:16>, when Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> when it returns an error code. Thus a pairing decrement is needed on
> the error handling path to keep the counter balanced.
>
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>
> Changelog:
>
> v2: -- Remove unnecessary 'err_clock' label
> ---
>  drivers/char/hw_random/exynos-trng.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
>

Reviewed-by: Lukasz Stelmach <l.stelmach@samsung.com>

Thank you.

> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
> index 8e1fe3f8dd2d..8393b898a50e 100644
> --- a/drivers/char/hw_random/exynos-trng.c
> +++ b/drivers/char/hw_random/exynos-trng.c
> @@ -142,13 +142,13 @@ static int exynos_trng_probe(struct platform_device *pdev)
>  	if (IS_ERR(trng->clk)) {
>  		ret = PTR_ERR(trng->clk);
>  		dev_err(&pdev->dev, "Could not get clock.\n");
> -		goto err_clock;
> +		goto err_pm_get;
>  	}
>  
>  	ret = clk_prepare_enable(trng->clk);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Could not enable the clk.\n");
> -		goto err_clock;
> +		goto err_pm_get;
>  	}
>  
>  	ret = devm_hwrng_register(&pdev->dev, &trng->rng);
> @@ -164,10 +164,8 @@ static int exynos_trng_probe(struct platform_device *pdev)
>  err_register:
>  	clk_disable_unprepare(trng->clk);
>  
> -err_clock:
> -	pm_runtime_put_sync(&pdev->dev);
> -
>  err_pm_get:
> +	pm_runtime_put_sync(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  
>  	return ret;

-- 
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics

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