[PATCH v5 6/6] can: add bittiming check at interface open for CAN FD

[Oliver Hartkopp <socketcan@hartkopp.net>]

Additionally to have the second (data) bitrate available the data bitrate
has to be greater or equal to the arbitration bitrate in CAN FD.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
 drivers/net/can/dev.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 3154fe0..561ba8c 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -656,6 +656,14 @@ int open_candev(struct net_device *dev)
 		return -EINVAL;
 	}
 
+	/* For CAN FD the data bitrate has to be >= the arbitration bitrate */
+	if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
+	    (!candev_has_bitrate(&priv->data_bittiming) ||
+	     (priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
+		netdev_err(dev, "incorrect/missing data bit-timing\n");
+		return -EINVAL;
+	}
+
 	/* Switch carrier on if device was stopped while in bus-off state */
 	if (!netif_carrier_ok(dev))
 		netif_carrier_on(dev);
-- 
1.9.0