[PATCH 091/133] virtio: console: fix raising SIGIO after port unplug

[Kamal Mostafa]

3.8.13.7 -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
processes.

Fix by setting guest_connected to false after invoking the sigio
function.

Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 drivers/char/virtio_console.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 615804c..62834bc 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1557,12 +1557,14 @@ static void unplug_port(struct port *port)
 	spin_unlock_irq(&port->portdev->ports_lock);
 
 	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)) {
-- 
1.8.1.2

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