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| author | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2015-10-19 13:37:41 +0900 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2015-10-20 22:13:59 +0800 |
| commit | bd1dffb1424682ac5b5849e0998c26dffcd61d9e (patch) | |
| tree | 1abe5913bc55ac3c05da6f9dc15f6a391e80d1b7 /drivers/char | |
| parent | d7fd6075a205f19cd0c570c8b5badb8c69321d88 (diff) | |
| download | lwn-bd1dffb1424682ac5b5849e0998c26dffcd61d9e.tar.gz lwn-bd1dffb1424682ac5b5849e0998c26dffcd61d9e.zip | |
hwrng: exynos - Fix missing configuration after suspend to RAM
After suspend to RAM the device stopped to work with ETIMEDOUT error:
$ dd if=/dev/hwrng of=/dev/null bs=1 count=16
dd: reading `/dev/hwrng': Connection timed out
In the STATUS register the bits #5 (PRNG_DONE) and #1
(SEED_SETTING_DONE) were not set. Instead PRNG_ERROR (seventh bit) was
high.
After each system suspend initialize the seed to fix the error.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/hw_random/exynos-rng.c | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c index c117463642e3..dc06c78bc1d7 100644 --- a/drivers/char/hw_random/exynos-rng.c +++ b/drivers/char/hw_random/exynos-rng.c @@ -53,15 +53,11 @@ static void exynos_rng_writel(struct exynos_rng *rng, u32 val, u32 offset) __raw_writel(val, rng->mem + offset); } -static int exynos_init(struct hwrng *rng) +static int exynos_rng_configure(struct exynos_rng *exynos_rng) { - struct exynos_rng *exynos_rng = container_of(rng, - struct exynos_rng, rng); int i; int ret = 0; - pm_runtime_get_sync(exynos_rng->dev); - for (i = 0 ; i < 5 ; i++) exynos_rng_writel(exynos_rng, jiffies, EXYNOS_PRNG_SEED_OFFSET + 4*i); @@ -70,6 +66,17 @@ static int exynos_init(struct hwrng *rng) & SEED_SETTING_DONE)) ret = -EIO; + return ret; +} + +static int exynos_init(struct hwrng *rng) +{ + struct exynos_rng *exynos_rng = container_of(rng, + struct exynos_rng, rng); + int ret = 0; + + pm_runtime_get_sync(exynos_rng->dev); + ret = exynos_rng_configure(exynos_rng); pm_runtime_put_noidle(exynos_rng->dev); return ret; @@ -155,10 +162,31 @@ static int exynos_rng_runtime_resume(struct device *dev) return clk_prepare_enable(exynos_rng->clk); } + +static int exynos_rng_suspend(struct device *dev) +{ + return pm_runtime_force_suspend(dev); +} + +static int exynos_rng_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct exynos_rng *exynos_rng = platform_get_drvdata(pdev); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) + return ret; + + return exynos_rng_configure(exynos_rng); +} #endif -static UNIVERSAL_DEV_PM_OPS(exynos_rng_pm_ops, exynos_rng_runtime_suspend, - exynos_rng_runtime_resume, NULL); +static const struct dev_pm_ops exynos_rng_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(exynos_rng_suspend, exynos_rng_resume) + SET_RUNTIME_PM_OPS(exynos_rng_runtime_suspend, + exynos_rng_runtime_resume, NULL) +}; static struct platform_driver exynos_rng_driver = { .driver = { |