1 files changed, 12 insertions, 7 deletions

diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
index ec435cb25c4f..868e39fd42e4 100644
--- a/drivers/char/hw_random/via-rng.c
+++ b/drivers/char/hw_random/via-rng.c
@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/hw_random.h>
+#include <linux/delay.h>
 #include <asm/io.h>
 #include <asm/msr.h>
 #include <asm/cpufeature.h>
@@ -77,10 +78,11 @@ static inline u32 xstore(u32 *addr, u32 edx_in)
         return eax_out;
 }
 
-static int via_rng_data_present(struct hwrng *rng)
+static int via_rng_data_present(struct hwrng *rng, int wait)
 {
         u32 bytes_out;
         u32 *via_rng_datum = (u32 *)(&rng->priv);
+        int i;
 
         /* We choose the recommended 1-byte-per-instruction RNG rate,
          * for greater randomness at the expense of speed.  Larger
@@ -95,12 +97,15 @@ static int via_rng_data_present(struct hwrng *rng)
          * completes.
          */
 
-        *via_rng_datum = 0; /* paranoia, not really necessary */
-        bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
-        bytes_out &= VIA_XSTORE_CNT_MASK;
-        if (bytes_out == 0)
-                return 0;
-        return 1;
+        for (i = 0; i < 20; i++) {
+                *via_rng_datum = 0; /* paranoia, not really necessary */
+                bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
+                bytes_out &= VIA_XSTORE_CNT_MASK;
+                if (bytes_out || !wait)
+                        break;
+                udelay(10);
+        }
+        return bytes_out ? 1 : 0;
 }
 
 static int via_rng_data_read(struct hwrng *rng, u32 *data)