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

On 2/5/2026 7:38 PM, Loic Poulain wrote:
> 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?
> 
> 
> 
Will remove this line skb_copy_to_linear_data, as it does memcpy
again in same skb->data
>> +                       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
>>
>>