When suspend is called after pm_runtime_suspend, same callback is used and access to rng register is freezing system. By calling the pm_runtime_force_suspend, it first checks that runtime has been already done. Signed-off-by: Lionel Debieve <lionel.debieve@xxxxxx> --- drivers/char/hw_random/stm32-rng.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 0d2328da3b76..042860d97b15 100644 --- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -187,8 +187,13 @@ static int stm32_rng_runtime_resume(struct device *dev) } #endif -static UNIVERSAL_DEV_PM_OPS(stm32_rng_pm_ops, stm32_rng_runtime_suspend, - stm32_rng_runtime_resume, NULL); +static const struct dev_pm_ops stm32_rng_pm_ops = { + SET_RUNTIME_PM_OPS(stm32_rng_runtime_suspend, + stm32_rng_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) +}; + static const struct of_device_id stm32_rng_match[] = { { -- 2.15.1