On 19.10.2015 13:37, Krzysztof Kozlowski wrote:
> 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@xxxxxxxxxxx>
> ---
> drivers/char/hw_random/exynos-rng.c | 42 ++++++++++++++++++++++++++++++-------
> 1 file changed, 35 insertions(+), 7 deletions(-)
>
Oh, I forgot about stable.
Fixes: b329669ea0b5 ("hwrng: exynos - Add support for Exynos random
number generator")
Cc: <stable@xxxxxxxxxxxxxxx>
I'll add it in respin (if there would be such).
Best regards,
Krzysztof
> diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c
> index dfaaaafb8ddd..162adbda1b70 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 = {
>
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