Sn_SR register shows undefined 0x28 state of TCP socket

Question

Hi everyone! Can you please help me understand the root cause of the issue I faced. I’ve been searching on the Internet for a long time by with no luck. I’m using stm32f103 + W5500 board. Application is running on STM32 as a TCP server and uses raw TCP to communicate with clients. Everything works good if a TCP client consiquently sends request, receives for the whole response from server, and then sends next request and so on. But if a client sends next request before it receives the whole response from TCP server (my STM32+W5500 board), W5500 chip goes down on recieving this request during the current response is still being sent. I’m using this library https://github.com/Wiznet/ioLibrary_Driver/archive/master.zip getSn_SR(TCP_SOCKET) returns 0x28 status which is not documented in the datasheet and wizphy_getphylink() returns PHY_LINK_OFF Below is main part of the rx code in the interrupt IRQ: irq_val = getSn_IR(TCP_SOCKET); if (irq_val & Sn_IR_RECV) { // It means we receive a packet in socket TCP_SOCKET if ((rcvd_size = getSn_RX_RSR(TCP_SOCKET)) > 0) { uint16_t next_head; char data; while (rcvd_size--) { ret = recv(TCP_SOCKET, (uint8_t *)&data, 1); if (ret > 0) { next_head = (rxbuf.head + 1) & (RX_BUFFER_SIZE - 1); if(!hal.stream.enqueue_realtime_command(data, StreamType_Serial)) { rxbuf.data[rxbuf.head] = data; rxbuf.head = next_head; } } } } setSn_IR(TCP_SOCKET, Sn_IR_RECV); // Clearing RECV interrupt flag } Below is tx function: void ethWriteS (const char *s) { char *ptr = (char *)s; int32_t ret; uint16_t sent_size = 0, length = strlen(s); while(sent_size != length) { ret = send(TCP_SOCKET, (uint8_t *)ptr + sent_size, length - sent_size); if (ret >=0 ) { sent_size += ret; } else { //print_debug("Send error: %d
", ret); close(TCP_SOCKET); return; } } } Wireshark trace below. 192.168.1.70 is my TCP server (STM32+W5500) 192.168.1.3 is a TCP client. 192.168.1.70 was transmitting a response but unexpectedly client sends the next request (packet #411), and after that W5500 goes down with socket status 0x28. image962×240 9.38 KB

Eugeny · Answer

dmitriybabintsev: and wizphy_getphylink() returns PHY_LINK_OFF Is the link really off - link LED is off? dmitriybabintsev: W5500 chip goes down on recieving this request during the current response is still being sent. This is unclear, please rephrase.