Merge branch 'virtio-net-rq-coalescing' into main

Heng Qi says:

====================
virtio-net: unbreak vq resizing if vq coalescing is not supported

Currently, if the driver does not negotiate the vq coalescing feature
but supports vq resize, the vq resize action, which could have been
successfully executed, is interrupted due to the failure in configuring
the vq coalescing parameters. This issue needs to be fixed.

Changelog
=========
v3->v4:
  - Add a comment for patch[2/2].

v2->v3:
  - Break out the feature check and the fix into separate patches.

v1->v2:
  - Rephrase the subject.
  - Put the feature check inside the virtnet_send_{r,t}x_ctrl_coal_vq_cmd.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -3658,6 +3658,9 @@ static int virtnet_send_rx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
 {
 	int err;
 
+	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL))
+		return -EOPNOTSUPP;
+
 	err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue),
 					    max_usecs, max_packets);
 	if (err)
@@ -3675,6 +3678,9 @@ static int virtnet_send_tx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
 {
 	int err;
 
+	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL))
+		return -EOPNOTSUPP;
+
 	err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue),
 					    max_usecs, max_packets);
 	if (err)
@@ -3743,7 +3749,11 @@ static int virtnet_set_ringparam(struct net_device *dev,
 			err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i,
 							       vi->intr_coal_tx.max_usecs,
 							       vi->intr_coal_tx.max_packets);
-			if (err)
+
+			/* Don't break the tx resize action if the vq coalescing is not
+			 * supported. The same is true for rx resize below.
+			 */
+			if (err && err != -EOPNOTSUPP)
 				return err;
 		}
 
@@ -3758,7 +3768,7 @@ static int virtnet_set_ringparam(struct net_device *dev,
 							       vi->intr_coal_rx.max_usecs,
 							       vi->intr_coal_rx.max_packets);
 			mutex_unlock(&vi->rq[i].dim_lock);
-			if (err)
+			if (err && err != -EOPNOTSUPP)
 				return err;
 		}
 	}