From d7fd6075a205f19cd0c570c8b5badb8c69321d88 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski <k.kozlowski@samsung.com> Date: Mon, 19 Oct 2015 13:37:40 +0900 Subject: [PATCH] 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> --- drivers/char/hw_random/exynos-rng.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c index 73318e2a34ddd..c117463642e34 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); -- GitLab