1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c
index 556fd81fa815..c422e870dc52 100644
--- a/drivers/char/hw_random/amd-rng.c
+++ b/drivers/char/hw_random/amd-rng.c
@@ -28,6 +28,7 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/hw_random.h>
+#include <linux/delay.h>
 #include <asm/io.h>
 
 
@@ -52,11 +53,18 @@ MODULE_DEVICE_TABLE(pci, pci_tbl);
 static struct pci_dev *amd_pdev;
 
 
-static int amd_rng_data_present(struct hwrng *rng)
+static int amd_rng_data_present(struct hwrng *rng, int wait)
 {
         u32 pmbase = (u32)rng->priv;
+        int data, i;
 
-        return !!(inl(pmbase + 0xF4) & 1);
+        for (i = 0; i < 20; i++) {
+                data = !!(inl(pmbase + 0xF4) & 1);
+                if (data || !wait)
+                        break;
+                udelay(10);
+        }
+        return data;
 }
 
 static int amd_rng_data_read(struct hwrng *rng, u32 *data)