openwrt/target/linux/bcm27xx/patches-5.10/950-0021-bcm2835-rng-Avoid-initialising-if-already-enabled.patch
Álvaro Fernández Rojas 8299d1f057 bcm27xx: add kernel 5.10 support
Rebased RPi foundation patches on linux 5.10.59, removed applied and reverted
patches, wireless patches and defconfig patches.

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 4B v1.1 4G
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2021-08-21 19:07:07 +02:00

26 lines
840 B
Diff

From 102d9fbd0a8d762835a9f9a7917e9eace3a9d84e 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;
}