hwrng: bcm2835 - Read as much data as available

Read the requested number of data from the fifo

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index b1e8b78..75ca820 100644 (file)
--- 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 = {