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>

1 files changed, 15 insertions, 17 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 7671914be172..6207e3729923 100644
--- 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;