It was <2020-11-30 pon 21:01>, when Qinglang Miao wrote:
> pm_runtime_get_sync will increment pm usage counter even
> failed. Forgetting to putting operation will result in a
> reference leak here.
>
> Replace it with pm_runtime_resume_and_get to keep usage
> counter balanced. I remove err_clock label at the same.
>
> Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Suggested-by: Lukasz Stelmach <l.stelmach@xxxxxxxxxxx>
> Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>
> ---
> v2: remobe useless label as Lukasz suggested.
That is good too, but I meant using pm_runtime_resume_and_get() in
exynos_trng_resume() too. Please take a look at that function.
>
> drivers/char/hw_random/exynos-trng.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
> index 8e1fe3f8d..ffebb72e4 100644
> --- a/drivers/char/hw_random/exynos-trng.c
> +++ b/drivers/char/hw_random/exynos-trng.c
> @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev)
> return PTR_ERR(trng->mem);
>
> pm_runtime_enable(&pdev->dev);
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0) {
> dev_err(&pdev->dev, "Could not get runtime PM.\n");
> goto err_pm_get;
> @@ -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);
> @@ -164,9 +164,6 @@ 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_disable(&pdev->dev);
--
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics
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