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Commit f1925d78 authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Herbert Xu
Browse files

hwrng: exynos - Fix unbalanced PM runtime put on timeout error path 



In case of timeout during read operation, the exit path lacked PM
runtime put. This could lead to unbalanced runtime PM usage counter thus
leaving the device in an active state.

Fixes: d7fd6075 ("hwrng: exynos - Add timeout for waiting on init done")
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent f0d947ac

drivers/char/hw_random/exynos-rng.c

+7 −3
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ static int exynos_read(struct hwrng *rng, void *buf, 
						struct exynos_rng, rng);

	u32 *data = buf;

	int retry = 100;

	int ret = 4;



	pm_runtime_get_sync(exynos_rng->dev);
@@ -98,17 +99,20 @@ static int exynos_read(struct hwrng *rng, void *buf, 
	while (!(exynos_rng_readl(exynos_rng,

			EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE) && --retry)

		cpu_relax();

	if (!retry)

		return -ETIMEDOUT;

	if (!retry) {

		ret = -ETIMEDOUT;

		goto out;

	}



	exynos_rng_writel(exynos_rng, PRNG_DONE, EXYNOS_PRNG_STATUS_OFFSET);



	*data = exynos_rng_readl(exynos_rng, EXYNOS_PRNG_OUT1_OFFSET);



out:

	pm_runtime_mark_last_busy(exynos_rng->dev);

	pm_runtime_put_sync_autosuspend(exynos_rng->dev);



	return 4;

	return ret;

}



static int exynos_rng_probe(struct platform_device *pdev)