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hwrng: exynos - Add timeout for waiting on init done

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Driver may hang waiting indefinitely for PRNG to finish its
initialization stage. Instead of stalling return -ETIMEDOUT error.

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 2015-10-19 13:37:40 +09:00 committed by Herbert Xu
parent 2b748a2f64
commit d7fd6075a2
1 changed files with 4 additions and 1 deletions
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5
drivers/char/hw_random/exynos-rng.c
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@ -81,14 +81,17 @@ static int exynos_read(struct hwrng *rng, void *buf,
struct exynos_rng *exynos_rng = container_of(rng,
struct exynos_rng, rng);
u32 *data = buf;
int retry = 100;
pm_runtime_get_sync(exynos_rng->dev);
exynos_rng_writel(exynos_rng, PRNG_START, 0);
while (!(exynos_rng_readl(exynos_rng,
EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE))
EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE) && --retry)
cpu_relax();
if (!retry)
return -ETIMEDOUT;
exynos_rng_writel(exynos_rng, PRNG_DONE, EXYNOS_PRNG_STATUS_OFFSET);