From a831b9132065e1aa18acd7910d5f9c164a2f350f Mon Sep 17 00:00:00 2001
From: Samuel Ortiz <sameo@linux.intel.com>
Date: Thu, 28 Jun 2012 16:41:57 +0200
Subject: NFC: Do not return EBUSY when stopping a poll that's already stopped

We check for the polling flag before checking if the netlink PID caller
match.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 03c31db..99bc6f7 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -634,6 +634,15 @@ static int nfc_genl_stop_poll(struct sk_buff *skb, struct genl_info *info)
 	if (!dev)
 		return -ENODEV;
 
+	device_lock(&dev->dev);
+
+	if (!dev->polling) {
+		device_unlock(&dev->dev);
+		return -EINVAL;
+	}
+
+	device_unlock(&dev->dev);
+
 	mutex_lock(&dev->genl_data.genl_data_mutex);
 
 	if (dev->genl_data.poll_req_pid != info->snd_pid) {
-- 
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