net: usb: qmi_wwan: restore mtu min/max values after raw_ip switch

usbnet creates network interfaces with min_mtu = 0 and
max_mtu = ETH_MAX_MTU.

These values are not modified by qmi_wwan when the network interface
is created initially, allowing, for example, to set mtu greater than 1500.

When a raw_ip switch is done (raw_ip set to 'Y', then set to 'N') the mtu
values for the network interface are set through ether_setup, with
min_mtu = ETH_MIN_MTU and max_mtu = ETH_DATA_LEN, not allowing anymore to
set mtu greater than 1500 (error: mtu greater than device maximum).

The patch restores the original min/max mtu values set by usbnet after a
raw_ip switch.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 3b7a3b8a5e067c4676afc7b20cb65c2af0e356bc..5754bb6ca0eeccc129b16b3b9ff433d067d00e34 100644 (file)
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -337,6 +337,9 @@ static void qmi_wwan_netdev_setup(struct net_device *net)
                netdev_dbg(net, "mode: raw IP\n");
        } else if (!net->header_ops) { /* don't bother if already set */
                ether_setup(net);
+               /* Restoring min/max mtu values set originally by usbnet */
+               net->min_mtu = 0;
+               net->max_mtu = ETH_MAX_MTU;
                clear_bit(EVENT_NO_IP_ALIGN, &dev->flags);
                netdev_dbg(net, "mode: Ethernet\n");
        }