Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for...

[sfrench/cifs-2.6.git] / drivers / char / hw_random / virtio-rng.c

diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index f3e71501de5409cb9947b851d2f689ab76545391..e9b15bc18b4d120ffcfb7441cee7cdeb2fca692e 100644 (file)
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -38,6 +38,8 @@ struct virtrng_info {
        int index;
 };
 
+static bool probe_done;
+
 static void random_recv_done(struct virtqueue *vq)
 {
        struct virtrng_info *vi = vq->vdev->priv;
@@ -67,6 +69,13 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
        int ret;
        struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
 
+       /*
+        * Don't ask host for data till we're setup.  This call can
+        * happen during hwrng_register(), after commit d9e7972619.
+        */
+       if (unlikely(!probe_done))
+               return 0;
+
        if (!vi->busy) {
                vi->busy = true;
                init_completion(&vi->have_data);
@@ -137,6 +146,7 @@ static int probe_common(struct virtio_device *vdev)
                return err;
        }
 
+       probe_done = true;
        return 0;
 }