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>
diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c
index 73318e2..c117463 100644
--- a/drivers/char/hw_random/exynos-rng.c
+++ b/drivers/char/hw_random/exynos-rng.c
@@ -81,14 +81,17 @@
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);