[PATCH 4.14 55/57] USB: Gadget Ethernet: Re-enable Jumbo frames.

From: Greg Kroah-Hartman
Date: Mon Feb 22 2021 - 08:23:29 EST


From: John Greb <h3x4m3r0n@xxxxxxxxx>

commit eea52743eb5654ec6f52b0e8b4aefec952543697 upstream

Fixes: <b3e3893e1253> ("net: use core MTU range checking")
which patched only one of two functions used to setup the
USB Gadget Ethernet driver, causing a serious performance
regression in the ability to increase mtu size above 1500.

Signed-off-by: John Greb <h3x4m3r0n@xxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/u_ether.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -850,6 +850,10 @@ struct net_device *gether_setup_name_def
net->ethtool_ops = &ops;
SET_NETDEV_DEVTYPE(net, &gadget_type);

+ /* MTU range: 14 - 15412 */
+ net->min_mtu = ETH_HLEN;
+ net->max_mtu = GETHER_MAX_ETH_FRAME_LEN;
+
return net;
}
EXPORT_SYMBOL_GPL(gether_setup_name_default);