[ 37/60] virtio: console: fix raising SIGIO after port unplug

From: Greg Kroah-Hartman
Date: Tue Aug 13 2013 - 02:50:59 EST

3.10-stable review patch. If anyone has any objections, please let me know.


From: Amit Shah <amit.shah@xxxxxxxxxx>

commit 92d3453815fbe74d539c86b60dab39ecdf01bb99 upstream.

SIGIO should be sent when a port gets unplugged. It should only be sent
to prcesses that have the port opened, and have asked for SIGIO to be
delivered. We were clearing out guest_connected before calling
send_sigio_to_port(), resulting in a sigio not getting sent to

Fix by setting guest_connected to false after invoking the sigio

Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/char/virtio_console.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1551,12 +1551,14 @@ static void unplug_port(struct port *por

if (port->guest_connected) {
+ /* Let the app know the port is going down. */
+ send_sigio_to_port(port);
+ /* Do this after sigio is actually sent */
port->guest_connected = false;
port->host_connected = false;
- wake_up_interruptible(&port->waitqueue);

- /* Let the app know the port is going down. */
- send_sigio_to_port(port);
+ wake_up_interruptible(&port->waitqueue);

if (is_console_port(port)) {

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