From: Sjur Brændeland Date: Mon, 18 Mar 2013 08:49:14 +0000 (+1030) Subject: Revert "virtio_console: Initialize guest_connected=true for rproc_serial" X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=aabd6a8fa5a933bdf968cd86e34122745c1960e8;p=linux-beck.git Revert "virtio_console: Initialize guest_connected=true for rproc_serial" This reverts commit 8078db789a92b10ff6e2d713231b5367e014c53b, and adds a lengthy comment explaining the problem area. The reverted patch caused opening of ports to fail for rproc_serial. In probe guest_connected was set to true, but port_fops_open() fails with -EMFILE if guest_connected already is true. Signed-off-by: Sjur Brændeland Acked-by: Amit Shah Signed-off-by: Rusty Russell --- diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index e905d5f53051..e6ba6b7887e9 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1436,7 +1436,7 @@ static int add_port(struct ports_device *portdev, u32 id) * rproc_serial does not want the console port, only * the generic port implementation. */ - port->host_connected = port->guest_connected = true; + port->host_connected = true; else if (!use_multiport(port->portdev)) { /* * If we're not using multiport support, @@ -1752,13 +1752,23 @@ static void in_intr(struct virtqueue *vq) port->inbuf = get_inbuf(port); /* - * Don't queue up data when port is closed. This condition + * Normally the port should not accept data when the port is + * closed. For generic serial ports, the host won't (shouldn't) + * send data till the guest is connected. But this condition * can be reached when a console port is not yet connected (no - * tty is spawned) and the host sends out data to console - * ports. For generic serial ports, the host won't - * (shouldn't) send data till the guest is connected. + * tty is spawned) and the other side sends out data over the + * vring, or when a remote devices start sending data before + * the ports are opened. + * + * A generic serial port will discard data if not connected, + * while console ports and rproc-serial ports accepts data at + * any time. rproc-serial is initiated with guest_connected to + * false because port_fops_open expects this. Console ports are + * hooked up with an HVC console and is initialized with + * guest_connected to true. */ - if (!port->guest_connected) + + if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev)) discard_port_data(port); spin_unlock_irqrestore(&port->inbuf_lock, flags);