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authorOliver Hartkopp <socketcan@hartkopp.net>2014-02-28 16:36:24 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2014-03-07 09:18:23 +0100
commitbc05a8944a344acdb81a65de055ca6febbf9657c (patch)
treebf3e474f5bac669b5a9d4b3d07aa7119875334fc /drivers/net/can
parent9859ccd2c8be63ce939522e63e265f2b0caa1109 (diff)
downloadop-kernel-dev-bc05a8944a344acdb81a65de055ca6febbf9657c.zip
op-kernel-dev-bc05a8944a344acdb81a65de055ca6febbf9657c.tar.gz
can: allow to change the device mtu for CAN FD capable devices
The configuration for CAN FD depends on CAN_CTRLMODE_FD enabled in the driver specific ctrlmode_supported capabilities. The configuration can be done either with the 'fd { on | off }' option in the 'ip' tool from iproute2 or by setting the CAN netdevice MTU to CAN_MTU (16) or to CANFD_MTU (72). Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/dev.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 8ebe112..4e20d82b 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -595,6 +595,39 @@ void free_candev(struct net_device *dev)
EXPORT_SYMBOL_GPL(free_candev);
/*
+ * changing MTU and control mode for CAN/CANFD devices
+ */
+int can_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct can_priv *priv = netdev_priv(dev);
+
+ /* Do not allow changing the MTU while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+
+ /* allow change of MTU according to the CANFD ability of the device */
+ switch (new_mtu) {
+ case CAN_MTU:
+ priv->ctrlmode &= ~CAN_CTRLMODE_FD;
+ break;
+
+ case CANFD_MTU:
+ if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD))
+ return -EINVAL;
+
+ priv->ctrlmode |= CAN_CTRLMODE_FD;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ dev->mtu = new_mtu;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(can_change_mtu);
+
+/*
* Common open function when the device gets opened.
*
* This function should be called in the open function of the device
@@ -693,6 +726,12 @@ static int can_changelink(struct net_device *dev,
return -EOPNOTSUPP;
priv->ctrlmode &= ~cm->mask;
priv->ctrlmode |= cm->flags;
+
+ /* CAN_CTRLMODE_FD can only be set when driver supports FD */
+ if (priv->ctrlmode & CAN_CTRLMODE_FD)
+ dev->mtu = CANFD_MTU;
+ else
+ dev->mtu = CAN_MTU;
}
if (data[IFLA_CAN_RESTART_MS]) {
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