diff options
| author | Vincent Mailhol <mailhol@kernel.org> | 2025-09-23 15:37:10 +0900 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2025-09-24 17:04:22 +0200 |
| commit | 23049938605bda390f875ce20e0704252c2e5c3d (patch) | |
| tree | a954b6e3aee37abc2085e3334e815cfd5386d73a /drivers/net/can/dev/dev.c | |
| parent | 7c7da8aa3fd69b77e8efaa14b80bddd948547739 (diff) | |
can: populate the minimum and maximum MTU values
By populating:
net_device->min_mtu
and
net_device->max_mtu
the net core infrastructure will automatically:
1. validate that the user's inputs are in range.
2. report those min and max MTU values through the netlink
interface.
Add can_set_default_mtu() which sets the default mtu value as well as
the minimum and maximum values. The logic for the default mtu value
remains unchanged:
- CANFD_MTU if the device has a static CAN_CTRLMODE_FD.
- CAN_MTU otherwise.
Call can_set_default_mtu() each time the CAN_CTRLMODE_FD is modified.
This will guarantee that the MTU value is always consistent with the
control mode flags.
With this, the checks done in can_change_mtu() become fully redundant
and will be removed in an upcoming change and it is now possible to
confirm the minimum and maximum MTU values on a physical CAN interface
by doing:
$ ip --details link show can0
The virtual interfaces (vcan and vxcan) are not impacted by this
change.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-can-fix-mtu-v3-3-581bde113f52@kernel.org
[mkl: squashed https://patch.msgid.link/20250924143644.17622-2-mailhol@kernel.org]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/dev/dev.c')
| -rw-r--r-- | drivers/net/can/dev/dev.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index 02bfed37cc93..befdeb4c54c2 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -240,6 +240,8 @@ void can_setup(struct net_device *dev) { dev->type = ARPHRD_CAN; dev->mtu = CAN_MTU; + dev->min_mtu = CAN_MTU; + dev->max_mtu = CAN_MTU; dev->hard_header_len = 0; dev->addr_len = 0; dev->tx_queue_len = 10; @@ -309,6 +311,21 @@ void free_candev(struct net_device *dev) } EXPORT_SYMBOL_GPL(free_candev); +void can_set_default_mtu(struct net_device *dev) +{ + struct can_priv *priv = netdev_priv(dev); + + if (priv->ctrlmode & CAN_CTRLMODE_FD) { + dev->mtu = CANFD_MTU; + dev->min_mtu = CANFD_MTU; + dev->max_mtu = CANFD_MTU; + } else { + dev->mtu = CAN_MTU; + dev->min_mtu = CAN_MTU; + dev->max_mtu = CAN_MTU; + } +} + /* changing MTU and control mode for CAN/CANFD devices */ int can_change_mtu(struct net_device *dev, int new_mtu) { @@ -361,8 +378,7 @@ int can_set_static_ctrlmode(struct net_device *dev, u32 static_mode) priv->ctrlmode = static_mode; /* override MTU which was set by default in can_setup()? */ - if (static_mode & CAN_CTRLMODE_FD) - dev->mtu = CANFD_MTU; + can_set_default_mtu(dev); return 0; } |