virtio: console: Don't always create a port 0 if using multiport

If we're using multiport, there's no point in always creating a console
port. Create the console port only if the host doesn't support
multiport.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 7671914..6207e37 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -784,6 +784,13 @@ int init_port_console(struct port *port)
        spin_unlock_irq(&pdrvdata_lock);
        port->guest_connected = true;
 
+       /*
+        * Start using the new console output if this is the first
+        * console to come up.
+        */
+       if (early_put_chars)
+               early_put_chars = NULL;
+
        /* Notify host of port being opened */
        send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
 
@@ -1058,14 +1065,8 @@ static void handle_control_message(struct ports_device *portdev,
        switch (cpkt->event) {
        case VIRTIO_CONSOLE_PORT_ADD:
                if (port) {
-                       /*
-                        * This can happen for port 0: we have to
-                        * create a console port during probe() as was
-                        * the behaviour before the MULTIPORT feature.
-                        * On a newer host, when the host tells us
-                        * that a port 0 is available, we should just
-                        * say we have the port all set up.
-                        */
+                       dev_dbg(&portdev->vdev->dev,
+                               "Port %u already added\n", port->id);
                        send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
                        break;
                }
@@ -1409,17 +1410,14 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
                        err = -ENOMEM;
                        goto free_vqs;
                }
+       } else {
+               /*
+                * For backward compatibility: Create a console port
+                * if we're running on older host.
+                */
+               add_port(portdev, 0);
        }
 
-       /*
-        * For backward compatibility: if we're running on an older
-        * host, we always want to create a console port.
-        */
-       add_port(portdev, 0);
-
-       /* Start using the new console output. */
-       early_put_chars = NULL;
-
        __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
                           VIRTIO_CONSOLE_DEVICE_READY, 1);
        return 0;