On 04/10/2019 16:26, Herbert Xu wrote: > On Thu, Sep 12, 2019 at 03:30:22PM +0200, Laurent Vivier wrote: >> >> @@ -496,19 +510,24 @@ int hwrng_register(struct hwrng *rng) >> goto out_unlock; >> } >> >> - if (old_rng && !rng->init) { >> + new_rng = rng; >> + kref_get(&new_rng->ref); >> +out_unlock: >> + mutex_unlock(&rng_mutex); >> + >> + if (new_rng) { >> + if (new_rng != old_rng || !rng->init) { > > Is this really supposed to be || instead of &&? original code calls add_early_randomness(): 1- everytime a new device is plugged in except if there is an init function (because if there is an init function it has not been called and it is needed to be able to use the device) 2- everytime current device is changed, unconditionally because in this case the init function has already been called. (in hwrng_init() in set_current_rng()) "new_rng != old_rng" is for 2-, and "!rng->init" is for 1-. So, yes, it's supposed to be "||". Thanks, Laurent