xen-netback: make feature-rx-notify mandatory
Frontends that do not provide feature-rx-notify may stall because
netback depends on the notification from frontend to wake the guest Rx
thread (even if can_queue is false).
This could be fixed but feature-rx-notify was introduced in 2006 and I
am not aware of any frontends that do not implement this.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 8079c31..9060857 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -873,15 +873,10 @@
if (!rx_copy)
return -EOPNOTSUPP;
- if (vif->dev->tx_queue_len != 0) {
- if (xenbus_scanf(XBT_NIL, dev->otherend,
- "feature-rx-notify", "%d", &val) < 0)
- val = 0;
- if (val)
- vif->can_queue = 1;
- else
- /* Must be non-zero for pfifo_fast to work. */
- vif->dev->tx_queue_len = 1;
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
+ "feature-rx-notify", "%d", &val) < 0 || val == 0) {
+ xenbus_dev_fatal(dev, -EINVAL, "feature-rx-notify is mandatory");
+ return -EINVAL;
}
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",