From 8529a504273d4efa6bb004dcd6ef28fe67b64ae9 Mon Sep 17 00:00:00 2001
From: Amit Shah <amit.shah@redhat.com>
Date: Thu, 2 Sep 2010 18:11:44 +0530
Subject: [PATCH] virtio: console: Unblock poll on port hot-unplug

When a port is hot-unplugged while an app is blocked on poll(), unblock
the poll() and return.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/char/virtio_console.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 92f1f65d57a9..47b710ca4ab3 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -663,6 +663,10 @@ static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
 	port = filp->private_data;
 	poll_wait(filp, &port->waitqueue, wait);
 
+	if (!port->guest_connected) {
+		/* Port got unplugged */
+		return POLLHUP;
+	}
 	ret = 0;
 	if (!will_read_block(port))
 		ret |= POLLIN | POLLRDNORM;