From 5d37f1ed8bf4654f48c9e4b76021ee3813d18ac1 Mon Sep 17 00:00:00 2001 From: popcornmix Date: Tue, 6 Dec 2016 17:05:39 +0000 Subject: [PATCH] bcm2835-rng: Avoid initialising if already enabled Avoids the 0x40000 cycles of warmup again if firmware has already used it --- drivers/char/hw_random/bcm2835-rng.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/char/hw_random/bcm2835-rng.c +++ b/drivers/char/hw_random/bcm2835-rng.c @@ -106,8 +106,10 @@ static int bcm2835_rng_init(struct hwrng } /* set warm-up count & enable */ - rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS); - rng_writel(priv, RNG_RBGEN, RNG_CTRL); + if (!(rng_readl(priv, RNG_CTRL) & RNG_RBGEN)) { + rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS); + rng_writel(priv, RNG_RBGEN, RNG_CTRL); + } return ret; }