[PATCH 3.16.y-ckt 086/135] can: c_can: end pending transmission on network stop (ifdown)

[Luis Henriques]

3.16.7-ckt6 -stable review patch.  If anyone has any objections, please let me know.

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

From: Viktor Babrian <babrian.viktor at renyi.mta.hu>

commit 7ffd7b4e169d619e66928fe5d997723f2c6f1056 upstream.

Put controller into init mode in network stop to end pending transmissions. The
issue is observed in cases when transmitted frame is not acked.

Signed-off-by: Viktor Babrian <babrian.viktor at renyi.mta.hu>
Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/can/c_can/c_can.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 8e78bb48f5a4..60285820f7b4 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -611,6 +611,10 @@ static void c_can_stop(struct net_device *dev)
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	c_can_irq_control(priv, false);
+
+	/* put ctrl to init on stop to end ongoing transmission */
+	priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_INIT);
+
 	priv->can.state = CAN_STATE_STOPPED;
 }
 
-- 
2.1.4