1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
index f518b99f53f5..731c9046cf7b 100644
--- a/drivers/char/hw_random/atmel-rng.c
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -34,8 +34,15 @@ static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
         u32 *data = buf;
 
         /* data ready? */
-        if (readl(trng->base + TRNG_ODATA) & 1) {
+        if (readl(trng->base + TRNG_ISR) & 1) {
                 *data = readl(trng->base + TRNG_ODATA);
+                /*
+                  ensure data ready is only set again AFTER the next data
+                  word is ready in case it got set between checking ISR
+                  and reading ODATA, so we don't risk re-reading the
+                  same word
+                */
+                readl(trng->base + TRNG_ISR);
                 return 4;
         } else
                 return 0;