On Tue, Dec 5, 2017 at 1:35 PM, Łukasz Stelmach <l.stelmach@xxxxxxxxxxx> wrote: > Reseed PRNG after reading 65 kB of randomness. Although this may reduce > performance, in most casese the loss is not noticable. s/casese/cases/ s/noticable/noticeable/ Please explain why you want to reseed after 65 kB (as opposite to current implementation). Mention also why you are changing the time of reseed. > > Signed-off-by: Łukasz Stelmach <l.stelmach@xxxxxxxxxxx> > --- > drivers/crypto/exynos-rng.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) > > diff --git a/drivers/crypto/exynos-rng.c b/drivers/crypto/exynos-rng.c > index 002e9d2a83cc..0bf07a655813 100644 > --- a/drivers/crypto/exynos-rng.c > +++ b/drivers/crypto/exynos-rng.c > @@ -54,12 +54,15 @@ enum exynos_prng_type { > }; > > /* > - * Driver re-seeds itself with generated random numbers to increase > - * the randomness. > + * Driver re-seeds itself with generated random numbers to hinder > + * backtracking of the original seed. > * > * Time for next re-seed in ms. > */ > -#define EXYNOS_RNG_RESEED_TIME 100 > +#define EXYNOS_RNG_RESEED_TIME 1000 > +#define EXYNOS_RNG_RESEED_BYTES 65536 > + > + Just one empty line. > /* > * In polling mode, do not wait infinitely for the engine to finish the work. > */ > @@ -81,6 +84,8 @@ struct exynos_rng_dev { > unsigned int seed_save_len; > /* Time of last seeding in jiffies */ > unsigned long last_seeding; > + /* Bytes generated since last seeding */ > + unsigned long bytes_seeding; > }; > > static struct exynos_rng_dev *exynos_rng_dev; > @@ -125,6 +130,7 @@ static int exynos_rng_set_seed(struct exynos_rng_dev *rng, > } > > rng->last_seeding = jiffies; > + rng->bytes_seeding = 0; > > return 0; > } > @@ -166,6 +172,8 @@ static int exynos_rng_get_random(struct exynos_rng_dev *rng, > memcpy_fromio(dst, rng->mem + EXYNOS_RNG_OUT_BASE, *read); > > return 0; > + > + No need for these lines. Best regards, Krzysztof