Re: [lwip-users] how to set the link up

[Krzysztof Wesołowski]

One simplification would be to do those link monitoring operations on timer running on LwIP thread, it removes threading issues (ie. Modifying stack data, accessing PHY). Only dhcp/ip setup would need to come from external memory/queue.

On Fri, 7 Jul 2017, 18:52 massimiliano cialdi, <address@hidden> wrote:

On 07/07/2017 18:04, Noam Weissman wrote:
>
> Speed, duplex, link etc... is low level handling and the TCP stack is
> not aware of that.
>
>
> This is why you call the set_link_up/down in your task, informing the
> stack !.
>
Yes, of course

> The MDIO interface between your micro and PHY has no relation with
> netif so why do you
>
> pass it as argument ?
>
because, in our implementation (NXP), netif->state is pointer to
structure containing information to interface with PHY.

> You several options to get the link state. You can connect the link
> led in the ETH connector
>
> to your micro and read it as a simple IO.
>
>
> If your PHY supports MII and it is connected as an MII you can hook an
> interrupt to the link line.
>
We are compliant to RMII, except interrupt signal that is not routed, so
we have to poll PHY.

> The third option is what I suggested to read the PHY basic register
> and check for the link bit.
>
Is what I do.

> Your link task should not only check if link is up or down but also
> know if it has changed !!. In your
>
> code is constantly calling the netifapi functions unless I missed
> something ?
>
Yes, I have further modified the task:

static void PhyStatus_Task( struct netif *netif )
{
     enum { link_up, link_down } linkstatus = link_down;
     phy_speed_t physpeed;
     phy_duplex_t phyduplex;
     bool link;
     status_t result;

     ETHSPDOFF();
     netifapi_netif_set_link_down(netif);
     while(1)
     {
         result = ethernetif_GetLinkStatus(netif, &link);
         if(result == kStatus_Success)
         {
             switch(linkstatus)
             {
             case link_down:
                 if(true == link)
                 {
                     linkstatus = link_up;
                     netifapi_netif_set_link_up(netif);
                 }
                 break;
             case link_up:
                 if(false == link)
                 {
                     linkstatus = link_down;
                     netifapi_netif_set_link_down(netif);
                     ETHSPDOFF();
                 }
                 else
                 {
                     result = ethernetif_GetLinkSpeedDuplex(netif,
&physpeed, &phyduplex);
                     if(result == kStatus_Success)
                     {
                         ETHSPD(physpeed);
                     }
                 }
                 break;
             }
         }
         vTaskDelay(100);
     }
}


I have investigated the problems: netifapi_netif_set_link_up() is called
and it cause call to link callback, in this function I call another
function in netifapi (netifapi_dhcp_start()), so I have a deadlock.

best regards
Max

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Pozdrawiam,

Krzysztof Wesołowski

+48 721 337 238