The rng structure contains the quality field which tells how many bits of entropy can be obtained from 1024 bits read from a device. With the quality value set the hw_random framework starts a kernel thread to feed the entropy pool in the CRNG, which helps to initialize it quickly especially during boot. Łukasz Stelmach (2): hwrng: iproc-rng200 - Set the quality value hwrng: exynos - Set the quality value drivers/char/hw_random/exynos-trng.c | 1 + drivers/char/hw_random/iproc-rng200.c | 1 + 2 files changed, 2 insertions(+) v2: - recalculated values using the SP800-90B_EntropyAssessment package -- 2.25.0