From 4f8de65bab611a68f40355ac9169edb4d0d33974 Mon Sep 17 00:00:00 2001 From: Yendapally Reddy Dhananjaya Reddy Date: Fri, 27 May 2016 06:10:41 -0400 Subject: [PATCH] hwrng: bcm2835 - Read as much data as available Read the requested number of data from the fifo Signed-off-by: Yendapally Reddy Dhananjaya Reddy Reviewed-by: Eric Anholt Signed-off-by: Herbert Xu --- drivers/char/hw_random/bcm2835-rng.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c index b1e8b7847e9a..75ca820730be 100644 --- a/drivers/char/hw_random/bcm2835-rng.c +++ b/drivers/char/hw_random/bcm2835-rng.c @@ -43,6 +43,8 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { void __iomem *rng_base = (void __iomem *)rng->priv; + u32 max_words = max / sizeof(u32); + u32 num_words, count; while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) { if (!wait) @@ -50,8 +52,14 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, cpu_relax(); } - *(u32 *)buf = __raw_readl(rng_base + RNG_DATA); - return sizeof(u32); + num_words = readl(rng_base + RNG_STATUS) >> 24; + if (num_words > max_words) + num_words = max_words; + + for (count = 0; count < num_words; count++) + ((u32 *)buf)[count] = readl(rng_base + RNG_DATA); + + return num_words * sizeof(u32); } static struct hwrng bcm2835_rng_ops = { -- 2.45.2