V4L/DVB (13906): cx18: Start IDX streams automatically as an internal associated...

[safe/jmp/linux-2.6] / drivers / virtio / virtio_ring.c

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index a882f26..fbd2ecd 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -208,7 +208,11 @@ add_head:
 
        pr_debug("Added buffer head %i to %p\n", head, vq);
        END_USE(vq);
-       return 0;
+
+       /* If we're indirect, we can fit many (assuming not OOM). */
+       if (vq->indirect)
+               return vq->num_free ? vq->vring.num : 0;
+       return vq->num_free;
 }
 
 static void vring_kick(struct virtqueue *_vq)
@@ -281,6 +285,9 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
                return NULL;
        }
 
+       /* Only get used array entries after they have been exposed by host. */
+       rmb();
+
        i = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].id;
        *len = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].len;