brcm2708: add linux 4.9 support

[openwrt/staging/yousong.git] / target / linux / brcm2708 / patches-4.9 / 0027-bcm2835-rng-Avoid-initialising-if-already-enabled.patch

diff --git a/target/linux/brcm2708/patches-4.9/0027-bcm2835-rng-Avoid-initialising-if-already-enabled.patch b/target/linux/brcm2708/patches-4.9/0027-bcm2835-rng-Avoid-initialising-if-already-enabled.patch
new file mode 100644 (file)
index 0000000..1fb2184
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.9/0027-bcm2835-rng-Avoid-initialising-if-already-enabled.patch
@@ -0,0 +1,26 @@
+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) {