[PATCH net-next 3/4] atl1c: adjust max mtu according to Mikrotik 10/25G NIC ability

From: Gatis Peisenieks
Date: Mon Apr 19 2021 - 10:35:20 EST


The new Mikrotik 10/25G NIC supports jumbo frames. Jumbo frames are
supported for TSO as well.

This enables the support for mtu up to 9500 bytes.

Signed-off-by: Gatis Peisenieks <gatis@xxxxxxxxxxxx>
---
drivers/net/ethernet/atheros/atl1c/atl1c_main.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index 8b097964a035..920e408ce7b4 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -478,6 +478,8 @@ static void atl1c_set_rxbufsize(struct atl1c_adapter *adapter,
static netdev_features_t atl1c_fix_features(struct net_device *netdev,
netdev_features_t features)
{
+ struct atl1c_adapter *adapter = netdev_priv(netdev);
+ struct atl1c_hw *hw = &adapter->hw;
/*
* Since there is no support for separate rx/tx vlan accel
* enable/disable make sure tx flag is always in same state as rx.
@@ -487,8 +489,10 @@ static netdev_features_t atl1c_fix_features(struct net_device *netdev,
else
features &= ~NETIF_F_HW_VLAN_CTAG_TX;

- if (netdev->mtu > MAX_TSO_FRAME_SIZE)
- features &= ~(NETIF_F_TSO | NETIF_F_TSO6);
+ if (hw->nic_type != athr_mt) {
+ if (netdev->mtu > MAX_TSO_FRAME_SIZE)
+ features &= ~(NETIF_F_TSO | NETIF_F_TSO6);
+ }

return features;
}
@@ -517,6 +521,9 @@ static void atl1c_set_max_mtu(struct net_device *netdev)
netdev->max_mtu = MAX_JUMBO_FRAME_SIZE -
(ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
break;
+ case athr_mt:
+ netdev->max_mtu = 9500;
+ break;
/* The 10/100 devices don't support jumbo packets, max_mtu 1500 */
default:
netdev->max_mtu = ETH_DATA_LEN;
--
2.31.1