LWIP sockets problem

[potap104]

I'm using the lwip socket library to send data to a server and found a problem.
I'm sending data in 3200 byte chunks using lwip_write().
After sending each fragment I use lwip_read() to get the response from the server.
After several reception and transmission cycles (about three), the bl602 freezes and stops transmitting data.
I discovered that at some point the sys_arch_sem_wait(sem, 0) function is called, which blocks the TCPIP task from executing.
What could be causing this blocking?
Thanks!

[yyipk]

The interface is blocked when sending TCP data because TCP needs to wait for the ACK from the peer. Here, sys_arch_sem_wait is likely waiting for the ACK to be received.