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| author | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2015-10-19 13:37:40 +0900 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2015-10-20 22:13:59 +0800 |
| commit | d7fd6075a205f19cd0c570c8b5badb8c69321d88 (patch) | |
| tree | e97a6a45a944b77072125790a921cff7b1c6d3c8 | |
| parent | 2b748a2f642a95c8125bfd8981d430a4e4d73e15 (diff) | |
| download | linux-d7fd6075a205f19cd0c570c8b5badb8c69321d88.tar.gz linux-d7fd6075a205f19cd0c570c8b5badb8c69321d88.tar.bz2 linux-d7fd6075a205f19cd0c570c8b5badb8c69321d88.zip | |
hwrng: exynos - Add timeout for waiting on init done
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>
| -rw-r--r-- | drivers/char/hw_random/exynos-rng.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c index 73318e2a34dd..c117463642e3 100644 --- a/drivers/char/hw_random/exynos-rng.c +++ b/drivers/char/hw_random/exynos-rng.c @@ -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); |