[PATCH net 1/4] net:ethernet:aquantia: Setup max_mtu in ndev to enable jumbo frames

[Igor Russkikh]

Although hardware is capable for almost 16K MTU, without max_mtu field
correctly set it only allows standard MTU to be used.
This patch enables max MTU, calculating it from hardware maximum frame size
of 16352 octets (including FCS).

Fixes: 5513e16421cb ("net: ethernet: aquantia: Fixes for aq_ndev_change_mtu")

Signed-off-by: Pavel Belous <pavel.bel...@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russk...@aquantia.com>
---
 drivers/net/ethernet/aquantia/atlantic/aq_nic.c                    | 5 +++--
 drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0_internal.h | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_nic.c 
b/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
index 6ac9e26..f281392 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_nic.c
@@ -214,7 +214,6 @@ struct aq_nic_s *aq_nic_alloc_cold(const struct 
net_device_ops *ndev_ops,
        SET_NETDEV_DEV(ndev, dev);
 
        ndev->if_port = port;
-       ndev->min_mtu = ETH_MIN_MTU;
        self->ndev = ndev;
 
        self->aq_pci_func = aq_pci_func;
@@ -283,6 +282,8 @@ int aq_nic_ndev_init(struct aq_nic_s *self)
        self->ndev->features = aq_hw_caps->hw_features;
        self->ndev->priv_flags = aq_hw_caps->hw_priv_flags;
        self->ndev->mtu = aq_nic_cfg->mtu - ETH_HLEN;
+       self->ndev->min_mtu = ETH_MIN_MTU;
+       self->ndev->max_mtu = self->aq_hw_caps.mtu - ETH_FCS_LEN - ETH_HLEN;
 
        return 0;
 }
@@ -695,7 +696,7 @@ int aq_nic_set_mtu(struct aq_nic_s *self, int new_mtu)
 {
        int err = 0;
 
-       if (new_mtu > self->aq_hw_caps.mtu) {
+       if (new_mtu + ETH_FCS_LEN > self->aq_hw_caps.mtu) {
                err = -EINVAL;
                goto err_exit;
        }
diff --git a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0_internal.h 
b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0_internal.h
index f3957e93..fcf89e2 100644
--- a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0_internal.h
+++ b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0_internal.h
@@ -16,7 +16,7 @@
 
 #include "../aq_common.h"
 
-#define HW_ATL_B0_MTU_JUMBO (16000U)
+#define HW_ATL_B0_MTU_JUMBO  16352U
 #define HW_ATL_B0_MTU        1514U
 
 #define HW_ATL_B0_TX_RINGS 4U
-- 
2.7.4