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

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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: d7fd6075a205 ("hwrng: exynos - Add timeout for waiting on init done")
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Krzysztof Kozlowski 2016-03-14 09:07:13 +09:00 committed by Herbert Xu
parent f0d947ac01
commit f1925d78d7
1 changed files with 7 additions and 3 deletions
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10
drivers/char/hw_random/exynos-rng.c
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@ -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)