diff options
Diffstat (limited to 'drivers/net/usb/cdc_ncm.c')
| -rw-r--r-- | drivers/net/usb/cdc_ncm.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 369405271437..e8a1144c5a8b 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -41,6 +41,7 @@ #include <linux/module.h> #include <linux/netdevice.h> #include <linux/ctype.h> +#include <linux/etherdevice.h> #include <linux/ethtool.h> #include <linux/workqueue.h> #include <linux/mii.h> @@ -689,6 +690,33 @@ static void cdc_ncm_free(struct cdc_ncm_ctx *ctx) kfree(ctx); } +/* we need to override the usbnet change_mtu ndo for two reasons: + * - respect the negotiated maximum datagram size + * - avoid unwanted changes to rx and tx buffers + */ +int cdc_ncm_change_mtu(struct net_device *net, int new_mtu) +{ + struct usbnet *dev = netdev_priv(net); + struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; + int maxmtu = ctx->max_datagram_size - cdc_ncm_eth_hlen(dev); + + if (new_mtu <= 0 || new_mtu > maxmtu) + return -EINVAL; + net->mtu = new_mtu; + return 0; +} +EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu); + +static const struct net_device_ops cdc_ncm_netdev_ops = { + .ndo_open = usbnet_open, + .ndo_stop = usbnet_stop, + .ndo_start_xmit = usbnet_start_xmit, + .ndo_tx_timeout = usbnet_tx_timeout, + .ndo_change_mtu = cdc_ncm_change_mtu, + .ndo_set_mac_address = eth_mac_addr, + .ndo_validate_addr = eth_validate_addr, +}; + int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags) { struct cdc_ncm_ctx *ctx; @@ -823,6 +851,9 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_ /* add our sysfs attrs */ dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group; + /* must handle MTU changes */ + dev->net->netdev_ops = &cdc_ncm_netdev_ops; + return 0; error2: |