From ed48b544108aced8bce4a64cf99d0523fde5c1b4 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(-) diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c index e7dd457..f9a4a89 100644 --- 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 *rng) } /* 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; } -- 2.7.4