virtio: explicit enable_cb/disable_cb rather than callback return.

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 4b8138312750..7b0059f0f5d4 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -52,13 +52,12 @@ static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
         sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
 }
 
-static bool skb_xmit_done(struct virtqueue *rvq)
+static void skb_xmit_done(struct virtqueue *rvq)
 {
         struct virtnet_info *vi = rvq->vdev->priv;
 
         /* In case we were waiting for output buffers. */
         netif_wake_queue(vi->dev);
-        return true;
 }
 
 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
@@ -161,12 +160,14 @@ static void try_fill_recv(struct virtnet_info *vi)
         vi->rvq->vq_ops->kick(vi->rvq);
 }
 
-static bool skb_recv_done(struct virtqueue *rvq)
+static void skb_recv_done(struct virtqueue *rvq)
 {
         struct virtnet_info *vi = rvq->vdev->priv;
-        netif_rx_schedule(vi->dev, &vi->napi);
-        /* Suppress further interrupts. */
-        return false;
+        /* Schedule NAPI, Suppress further interrupts if successful. */
+        if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
+                rvq->vq_ops->disable_cb(rvq);
+                __netif_rx_schedule(vi->dev, &vi->napi);
+        }
 }
 
 static int virtnet_poll(struct napi_struct *napi, int budget)
@@ -192,7 +193,7 @@ again:
         /* Out of packets? */
         if (received < budget) {
                 netif_rx_complete(vi->dev, napi);
-                if (unlikely(!vi->rvq->vq_ops->restart(vi->rvq))
+                if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
                     && netif_rx_reschedule(vi->dev, napi))
                         goto again;
         }