4.9-stable review patch. If anyone has any objections, please let me know.
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From: "lionel.debieve@st.com" lionel.debieve@st.com
[ Upstream commit 326ed382256475aa4b8b7eae8a2f60689fd25e78 ]
Avoid issue when probing the RNG without reset if bad status has been detected previously
Signed-off-by: Lionel Debieve lionel.debieve@st.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/hw_random/stm32-rng.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -21,6 +21,7 @@ #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/pm_runtime.h> +#include <linux/reset.h> #include <linux/slab.h>
#define RNG_CR 0x00 @@ -46,6 +47,7 @@ struct stm32_rng_private { struct hwrng rng; void __iomem *base; struct clk *clk; + struct reset_control *rst; };
static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) @@ -140,6 +142,13 @@ static int stm32_rng_probe(struct platfo if (IS_ERR(priv->clk)) return PTR_ERR(priv->clk);
+ priv->rst = devm_reset_control_get(&ofdev->dev, NULL); + if (!IS_ERR(priv->rst)) { + reset_control_assert(priv->rst); + udelay(2); + reset_control_deassert(priv->rst); + } + dev_set_drvdata(dev, priv);
priv->rng.name = dev_driver_string(dev),