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

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

[Łukasz Stelmach]

pm_runtime_get_sync() increments the runtime PM usage counter even
the call returns an error code. Thus a pairing decrement is needed
on the error handling path to keep the counter balanced.

Change-Id: I028915fbee9e4a050a1313119872d6043696632d
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/char/hw_random/exynos-trng.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
index 8e1fe3f8dd2d..9f455d952e87 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_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
 	return ret;
-- 
2.26.2


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Re: [PATCH] hwrng: exynos - fix runtime pm imbalance on error

[Lukasz Stelmach]

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It was <2020-05-20 śro 21:19>, when Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> the call 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>
> ---
>  drivers/char/hw_random/exynos-trng.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
> index 8e1fe3f8dd2d..133e017db577 100644
> --- a/drivers/char/hw_random/exynos-trng.c
> +++ b/drivers/char/hw_random/exynos-trng.c
> @@ -165,9 +165,8 @@ static int exynos_trng_probe(struct platform_device *pdev)
>  	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;

You are right. I will accept the patch, when you remove the err_clock
label and and change goto instructions above to point to
err_pm_get. There is no point in having two labels.

Thank you.
-- 
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics

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[-- Attachment #2: Type: text/plain, Size: 176 bytes --]

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[PATCH] hwrng: exynos - fix runtime pm imbalance on error

[Dinghao Liu]

pm_runtime_get_sync() increments the runtime PM usage counter even
the call 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>
---
 drivers/char/hw_random/exynos-trng.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
index 8e1fe3f8dd2d..133e017db577 100644
--- a/drivers/char/hw_random/exynos-trng.c
+++ b/drivers/char/hw_random/exynos-trng.c
@@ -165,9 +165,8 @@ static int exynos_trng_probe(struct platform_device *pdev)
 	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;
-- 
2.17.1


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