openwrtv3/target/linux/brcm2708/patches-4.9/0027-bcm2835-rng-Avoid-initialising-if-already-enabled.patch
Álvaro Fernández Rojas 96aa0c6b0b brcm2708: add linux 4.9 support
Patches from Raspberry Pi repo:
https://github.com/raspberrypi/linux/commits/rpi-4.9.y

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2017-02-07 23:00:16 +01:00

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958 B
Diff

From a195976d635c3672cae684d6338655aa25f6d98c 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 | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- 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 plat
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) {