Phonet: fix accounting race between gprs_writeable() and gprs_xmit()

In the unlikely event that gprs_writeable() and gprs_xmit() check for
writeability at the same, we could stop the device queue forever.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/phonet/pep-gprs.c b/net/phonet/pep-gprs.c
index 4aa888584d20..851f6a3f8ddd 100644
--- a/net/phonet/pep-gprs.c
+++ b/net/phonet/pep-gprs.c
@@ -212,8 +212,9 @@ static int gprs_xmit(struct sk_buff *skb, struct net_device *dev)
                 dev->stats.tx_bytes += len;
         }
 
-        if (!pep_writeable(sk))
-                netif_stop_queue(dev);
+        netif_stop_queue(dev);
+        if (pep_writeable(sk))
+                netif_wake_queue(dev);
         return 0;
 }