openwrt/target/linux/bcm27xx/patches-5.15/950-0047-bcm2835-rng-Avoid-initialising-if-already-enabled.patch
Álvaro Fernández Rojas 20ea6adbf1 bcm27xx: add support for linux v5.15
Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2022-05-17 15:11:22 +02:00

26 lines
840 B
Diff

From d7e520c88cb8e7025c93c809350794711fc94f52 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
@@ -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;
}