From c5759d7c254f5e0c360a3ce9172b3972d0f13779 Mon Sep 17 00:00:00 2001 From: popcornmix Date: Tue, 6 Dec 2016 17:05:39 +0000 Subject: [PATCH 023/277] 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 | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c index 574211a49549..e66c0fca8c60 100644 --- a/drivers/char/hw_random/bcm2835-rng.c +++ b/drivers/char/hw_random/bcm2835-rng.c @@ -102,9 +102,10 @@ static int bcm2835_rng_probe(struct platform_device *pdev) rng_setup(rng_base); /* set warm-up count & enable */ - __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); - __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); - + if (!(__raw_readl(rng_base + RNG_CTRL) & RNG_RBGEN)) { + __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); + __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); + } /* register driver */ err = hwrng_register(&bcm2835_rng_ops); if (err) { -- 2.16.1