STM32H755ZI-Q: LAN8742,problem with ping after dhcp server gives ip address to the nucleo-board.All set-up made by example for STM32H745ZI-Q

[Al-Dzhavad]

Hi
I am trying to make simple setup for H755ZI-Q nucleo-board with ETH + LWIP + RTOS. I was using  this Forum Section as the source of example that i used (H745ZI-Q) that is by all documents have same characteristics as my board and compatible with it . 

So back to the Problem, my board doesn^t respond to ping that i send even when the dhcp server that i started on my PC gives me that the board on this “IP-address” . After what the ping don^t  go through.  I added a breakpoint to "void ETH_IRQHandler(void)". After the initial power-on, the system reaches the breakpoint three times even when there is no ping command on the Ethernet port. Can u please help me with that?

I tried to reconfigure everything from flash memory , turn off the Cache to check if that change anything , I have even Hybrid of RTOS + Raw Api ETH + LWIP that works. I could not understand is smth wrong with my board or with code that generates cause in Documents everything sounded simplier. 
 
My Project (Main Files)

Example that was used as Reference

[pavich]

Hello.
To enable ICMP you need to set up:

#define LWIP_ICMP 1
#define LWIP_IPV4 1

Also, please check that LWIP_ARP is 1. If everything looks fine, use Wireshark to capture packets — if you see something like "Checksum Error", you have a problem with your checksum settings.

Next, I suspect ETH_IRQn doesn't have an explicit HAL_NVIC_SetPriority call, so it stays at its default priority of 0 — the highest urgency in Cortex-M NVIC. Since osSemaphoreRelease (called inside HAL_ETH_RxCpltCallback) is an ISR-safe FreeRTOS API, the interrupt priority must be numerically ≥ configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY (5 in your config). Priority 0 violates this — DMA physically receives the frame, but the semaphore release may not safely propagate to the ethernetif_input task.

I haven't fully confirmed why DHCP would still succeed through the same RX path — worth checking that separately if the priority fix alone doesn't resolve it.

[Al-Dzhavad]

Hi.

I double checked everything u wrote  and is set right as u sayed arp 1 icmp 1 ipv4 1 but as u can see on the screenshot it boots without checksum errors so i can not confirm or deny what u said. 

So my last suggestion was the thread that makes MX_LWIP_INIT(); , I cant double check that cause it make my laptop crash CubeIDE and actually hard to be checked , but it the last thing i cant double check . 

memset(&attributes, 0x0, sizeof(osThreadAttr_t));

attributes.name = "EthLink";

attributes.stack_size = INTERFACE_THREAD_STACK_SIZE;

attributes.priority = osPriorityBelowNormal;

osThreadNew(ethernet_link_thread, &gnetif, &attributes);

This one cause it declare it self before dhcp_start so if it should take the connection and maintain it , it can not know the IP of the board.

UPD: I tried to install a break point in dhcp_start to check if it is first called or the thread but it just get ignored.

For any respond i would be greatful

Sincerly yours

Al-Dzhavad