[PATCH 3.18 03/45] cxgb4: avoid enabling napi twice to the same queue

[Greg Kroah-Hartman]

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

------------------

From: Ganesh Goudar <ganeshgr@xxxxxxxxxxx>


[ Upstream commit e7519f9926f1d0d11c776eb0475eb098c7760f68 ]

Take uld mutex to avoid race between cxgb_up() and
cxgb4_register_uld() to enable napi for the same uld
queue.

Signed-off-by: Ganesh Goudar <ganeshgr@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -4580,10 +4580,14 @@ static int cxgb_up(struct adapter *adap)
 		if (err)
 			goto irq_err;
 	}
+
+	mutex_lock(&uld_mutex);
 	enable_rx(adap);
 	t4_sge_start(adap);
 	t4_intr_enable(adap);
 	adap->flags |= FULL_INIT_DONE;
+	mutex_unlock(&uld_mutex);
+
 	notify_ulds(adap, CXGB4_STATE_UP);
 #if IS_ENABLED(CONFIG_IPV6)
 	update_clip(adap);