Re: [PATCH v7 1/2] net: mhi: Enable Ethernet interface support

Hi Vivek,

On Thu, Feb 5, 2026 at 11:35 AM Vivek Pernamitta
<[email protected]> wrote:
>
> From: Vivek Pernamitta <[email protected]>
>
> Add support to configure a new client as Ethernet type over MHI by
> setting "mhi_device_info.ethernet_if = true". Create a new Ethernet
> interface named eth%d. This complements existing NET driver support.
>
> Introduce IP_SW1, ETH0, and ETH1 network interfaces required for
> M-plane, NETCONF, and S-plane components.
>
> M-plane:
> Implement DU M-Plane software for non-real-time O-RAN management
> between O-DU and O-RU using NETCONF/YANG and O-RAN WG4 M-Plane YANG
> models. Provide capability exchange, configuration management,
> performance monitoring, and fault management per O-RAN.WG4.TS.MP.0-
> R004-v18.00.
>
> NETCONF:
> Use NETCONF protocol for configuration operations such as fetching,
> modifying, and deleting network device configurations.
>
> S-plane:
> Support frequency and time synchronization between O-DUs and O-RUs
> using Synchronous Ethernet and IEEE 1588. Assume PTP transport over
> L2 Ethernet (ITU-T G.8275.1) for full timing support; allow PTP over
> UDP/IP (ITU-T G.8275.2) with reduced reliability. as per ORAN spec
> O-RAN.WG4.CUS.0-R003-v12.00.
>
> Signed-off-by: Vivek Pernamitta <[email protected]>
> ---
>  drivers/net/mhi_net.c | 75 ++++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 62 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c
> index ae169929a9d8e449b5a427993abf68e8d032fae2..fbec10c1ba9faf1ccf049b808e9d391800320989 100644
> --- a/drivers/net/mhi_net.c
> +++ b/drivers/net/mhi_net.c
> @@ -4,6 +4,7 @@
>   * Copyright (C) 2020 Linaro Ltd <[email protected]>
>   */
>
> +#include <linux/etherdevice.h>
>  #include <linux/if_arp.h>
>  #include <linux/mhi.h>
>  #include <linux/mod_devicetable.h>
> @@ -38,10 +39,12 @@ struct mhi_net_dev {
>         u32 rx_queue_sz;
>         int msg_enable;
>         unsigned int mru;
> +       bool ethernet_if;
>  };
>
>  struct mhi_device_info {
>         const char *netname;
> +       bool ethernet_if;
>  };
>
>  static int mhi_ndo_open(struct net_device *ndev)
> @@ -119,11 +122,29 @@ static void mhi_ndo_get_stats64(struct net_device *ndev,
>         } while (u64_stats_fetch_retry(&mhi_netdev->stats.tx_syncp, start));
>  }
>
> +static int mhi_mac_address(struct net_device *dev, void *p)
> +{
> +       if (dev->type == ARPHRD_ETHER)
> +               return eth_mac_addr(dev, p);
> +
> +       return 0;
> +}
> +
> +static int mhi_validate_address(struct net_device *dev)
> +{
> +       if (dev->type == ARPHRD_ETHER)
> +               return eth_validate_addr(dev);
> +
> +       return 0;
> +}
> +
>  static const struct net_device_ops mhi_netdev_ops = {
>         .ndo_open               = mhi_ndo_open,
>         .ndo_stop               = mhi_ndo_stop,
>         .ndo_start_xmit         = mhi_ndo_xmit,
>         .ndo_get_stats64        = mhi_ndo_get_stats64,
> +       .ndo_set_mac_address    = mhi_mac_address,
> +       .ndo_validate_addr      = mhi_validate_address,
>  };
>
>  static void mhi_net_setup(struct net_device *ndev)
> @@ -140,6 +161,13 @@ static void mhi_net_setup(struct net_device *ndev)
>         ndev->tx_queue_len = 1000;
>  }
>
> +static void mhi_ethernet_setup(struct net_device *ndev)
> +{
> +       ndev->netdev_ops = &mhi_netdev_ops;
> +       ether_setup(ndev);
> +       ndev->max_mtu = ETH_MAX_MTU;
> +}
> +
>  static struct sk_buff *mhi_net_skb_agg(struct mhi_net_dev *mhi_netdev,
>                                        struct sk_buff *skb)
>  {
> @@ -209,16 +237,22 @@ static void mhi_net_dl_callback(struct mhi_device *mhi_dev,
>                         mhi_netdev->skbagg_head = NULL;
>                 }
>
> -               switch (skb->data[0] & 0xf0) {
> -               case 0x40:
> -                       skb->protocol = htons(ETH_P_IP);
> -                       break;
> -               case 0x60:
> -                       skb->protocol = htons(ETH_P_IPV6);
> -                       break;
> -               default:
> -                       skb->protocol = htons(ETH_P_MAP);
> -                       break;
> +               if (mhi_netdev->ethernet_if) {
> +                       skb_copy_to_linear_data(skb, skb->data,
> +                                               mhi_res->bytes_xferd);

What is the purpose of the above?




> +                       skb->protocol = eth_type_trans(skb, mhi_netdev->ndev);
> +               } else {
> +                       switch (skb->data[0] & 0xf0) {
> +                       case 0x40:
> +                               skb->protocol = htons(ETH_P_IP);
> +                               break;
> +                       case 0x60:
> +                               skb->protocol = htons(ETH_P_IPV6);
> +                               break;
> +                       default:
> +                               skb->protocol = htons(ETH_P_MAP);
> +                               break;
> +                       }
>                 }
>
>                 u64_stats_update_begin(&mhi_netdev->stats.rx_syncp);
> @@ -301,11 +335,14 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
>                 schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2);
>  }
>
> -static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
> +static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev, bool eth_dev)
>  {
>         struct mhi_net_dev *mhi_netdev;
>         int err;
>
> +       if (eth_dev)
> +               eth_hw_addr_random(ndev);
> +
>         mhi_netdev = netdev_priv(ndev);
>
>         dev_set_drvdata(&mhi_dev->dev, mhi_netdev);
> @@ -313,6 +350,7 @@ static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
>         mhi_netdev->mdev = mhi_dev;
>         mhi_netdev->skbagg_head = NULL;
>         mhi_netdev->mru = mhi_dev->mhi_cntrl->mru;
> +       mhi_netdev->ethernet_if = eth_dev;
>
>         INIT_DELAYED_WORK(&mhi_netdev->rx_refill, mhi_net_rx_refill_work);
>         u64_stats_init(&mhi_netdev->stats.rx_syncp);
> @@ -356,13 +394,14 @@ static int mhi_net_probe(struct mhi_device *mhi_dev,
>         int err;
>
>         ndev = alloc_netdev(sizeof(struct mhi_net_dev), info->netname,
> -                           NET_NAME_PREDICTABLE, mhi_net_setup);
> +                           NET_NAME_ENUM, info->ethernet_if ?
> +                           mhi_ethernet_setup : mhi_net_setup);
>         if (!ndev)
>                 return -ENOMEM;
>
>         SET_NETDEV_DEV(ndev, &mhi_dev->dev);
>
> -       err = mhi_net_newlink(mhi_dev, ndev);
> +       err = mhi_net_newlink(mhi_dev, ndev, info->ethernet_if);
>         if (err) {
>                 free_netdev(ndev);
>                 return err;
> @@ -380,10 +419,17 @@ static void mhi_net_remove(struct mhi_device *mhi_dev)
>
>  static const struct mhi_device_info mhi_hwip0 = {
>         .netname = "mhi_hwip%d",
> +       .ethernet_if = false,
>  };
>
>  static const struct mhi_device_info mhi_swip0 = {
>         .netname = "mhi_swip%d",
> +       .ethernet_if = false,
> +};
> +
> +static const struct mhi_device_info mhi_eth0 = {
> +       .netname = "eth%d",
> +       .ethernet_if = true,
>  };
>
>  static const struct mhi_device_id mhi_net_id_table[] = {
> @@ -391,6 +437,9 @@ static const struct mhi_device_id mhi_net_id_table[] = {
>         { .chan = "IP_HW0", .driver_data = (kernel_ulong_t)&mhi_hwip0 },
>         /* Software data PATH (to modem CPU) */
>         { .chan = "IP_SW0", .driver_data = (kernel_ulong_t)&mhi_swip0 },
> +       { .chan = "IP_SW1", .driver_data = (kernel_ulong_t)&mhi_swip0 },
> +       { .chan = "IP_ETH0", .driver_data = (kernel_ulong_t)&mhi_eth0 },
> +       { .chan = "IP_ETH1", .driver_data = (kernel_ulong_t)&mhi_eth0 },
>         {}
>  };
>  MODULE_DEVICE_TABLE(mhi, mhi_net_id_table);
>
> --
> 2.34.1
>
>