On 03/21/2018 11:58 AM, Richard Cochran wrote:
> This patch adds a new field to the network device structure to reference
> a time stamping device on the MII bus.  By decoupling the time stamping
> function from the PHY device, we pave the way to allowing a non-PHY
> device to take this role.
> 
> Signed-off-by: Richard Cochran <richardcoch...@gmail.com>
> ---
>  drivers/net/phy/mdio_bus.c | 51 
> +++++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/netdevice.h  |  1 +
>  2 files changed, 51 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 24b5511222c8..fdac8c8ac272 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -717,6 +717,47 @@ static int mdio_uevent(struct device *dev, struct 
> kobj_uevent_env *env)
>       return 0;
>  }
>  
> +static bool mdiodev_supports_timestamping(struct mdio_device *mdiodev)
> +{
> +     if (mdiodev->ts_info  && mdiodev->hwtstamp &&
> +         mdiodev->rxtstamp && mdiodev->txtstamp)
> +             return true;
> +     else
> +             return false;
> +}
> +
> +static int mdiobus_netdev_notification(struct notifier_block *nb,
> +                                    unsigned long msg, void *ptr)
> +{
> +     struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
> +     struct phy_device *phydev = netdev->phydev;
> +     struct mdio_device *mdev;
> +     struct mii_bus *bus;
> +     int i;
> +
> +     if (netdev->mdiots || msg != NETDEV_UP || !phydev)
> +             return NOTIFY_DONE;

You are still assuming that we have a phy_device somehow, whereas you
parch series wants to solve that for generic MDIO devices, that is a bit
confusing.

> +
> +     /*
> +      * Examine the MII bus associated with the PHY that is
> +      * attached to the MAC.  If there is a time stamping device
> +      * on the bus, then connect it to the network device.
> +      */
> +     bus = phydev->mdio.bus;
> +
> +     for (i = 0; i < PHY_MAX_ADDR; i++) {
> +             mdev = bus->mdio_map[i];
> +             if (!mdev)
> +                     continue;
> +             if (mdiodev_supports_timestamping(mdev)) {
> +                     netdev->mdiots = mdev;
> +                     return NOTIFY_OK;

What guarantees that netdev->mdiots gets cleared? Also, why is this done
with a notifier instead of through phy_{connect,attach,disconnect}? It
looks like we still have this requirement of the mdio TS device being a
phy_device somehow, I am confused here...

> +             }
> +     }
> +
> +     return NOTIFY_DONE;
> +}
> +
>  #ifdef CONFIG_PM
>  static int mdio_bus_suspend(struct device *dev)
>  {

> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 5fbb9f1da7fd..223d691aa0b0 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1943,6 +1943,7 @@ struct net_device {
>       struct netprio_map __rcu *priomap;
>  #endif
>       struct phy_device       *phydev;
> +     struct mdio_device      *mdiots;

phy_device embedds a mdio_device, can you find a way to rework the PHY
PTP code to utilize the phy_device's mdio instance so do not introduce
yet another pointer in that big structure that net_device already is?

>       struct lock_class_key   *qdisc_tx_busylock;
>       struct lock_class_key   *qdisc_running_key;
>       bool                    proto_down;
> 


-- 
Florian

Reply via email to