| From 5cf8059baa23779d979bcd8febe5ed4670e58fe3 Mon Sep 17 00:00:00 2001 |
| From: popcornmix <popcornmix@gmail.com> |
| 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 |
| @@ -102,8 +102,10 @@ 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; |
| } |