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From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
To: Kukjin Kim <kgene@kernel.org>,
	Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	Matt Mackall <mpm@selenic.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-crypto@vger.kernel.org
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Subject: [PATCH 2/4] hwrng: exynos - Add timeout for waiting on init done
Date: Mon, 19 Oct 2015 13:37:40 +0900	[thread overview]
Message-ID: <1445229462-32395-3-git-send-email-k.kozlowski@samsung.com> (raw)
In-Reply-To: <1445229462-32395-1-git-send-email-k.kozlowski@samsung.com>

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>
---
 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 dc4701fd814f..dfaaaafb8ddd 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);
 
-- 
1.9.1

WARNING: multiple messages have this Message-ID (diff)
From: k.kozlowski@samsung.com (Krzysztof Kozlowski)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/4] hwrng: exynos - Add timeout for waiting on init done
Date: Mon, 19 Oct 2015 13:37:40 +0900	[thread overview]
Message-ID: <1445229462-32395-3-git-send-email-k.kozlowski@samsung.com> (raw)
In-Reply-To: <1445229462-32395-1-git-send-email-k.kozlowski@samsung.com>

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>
---
 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 dc4701fd814f..dfaaaafb8ddd 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);
 
-- 
1.9.1

  parent reply	other threads:[~2015-10-19  4:37 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-19  4:37 [PATCH 0/4] hwrng: exynos - Add Device Tree support Krzysztof Kozlowski
2015-10-19  4:37 ` Krzysztof Kozlowski
2015-10-19  4:37 ` [PATCH 1/4] dt-bindings: rng: Describe Exynos4 PRNG bindings Krzysztof Kozlowski
2015-10-19  4:37   ` Krzysztof Kozlowski
2015-10-19  4:37 ` Krzysztof Kozlowski [this message]
2015-10-19  4:37   ` [PATCH 2/4] hwrng: exynos - Add timeout for waiting on init done Krzysztof Kozlowski
2015-10-19  4:37 ` [PATCH 4/4] hwrng: exynos - Add Device Tree support Krzysztof Kozlowski
2015-10-19  4:37   ` Krzysztof Kozlowski
     [not found] ` <1445229462-32395-1-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2015-10-19  4:37   ` [PATCH 3/4] hwrng: exynos - Fix missing configuration after suspend to RAM Krzysztof Kozlowski
2015-10-19  4:37     ` Krzysztof Kozlowski
2015-10-19  4:37     ` Krzysztof Kozlowski
2015-10-19  5:03     ` Krzysztof Kozlowski
2015-10-19  5:03       ` Krzysztof Kozlowski
2015-10-20 14:24   ` [PATCH 0/4] hwrng: exynos - Add Device Tree support Herbert Xu
2015-10-20 14:24     ` Herbert Xu
2015-10-20 14:24     ` Herbert Xu

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