Interrupt driven socket interface

Question

Hello, I’m working on a general interrupt driven socket interface to W5500 using a RX600 from Renesas and FreeRTOS. UDP communication seems to work well. Although TCP communication with listen, send and receive works fine with interrupt system. In the next step I want to make the driver more fault-tolerant to network errors or to unpredictable events. Now I wonder why there is no interrupt for “Closed”. What will happen if my interface receives a RST packet from a peer? Let’s take for example the CONNECT command (0x04). If the connect is successful I will get a CON interrupt (0). At a timeout (ARP or TCP) there will be a TIMEOUT interrupt (3). But what happens if the server sends a RST. The socket changes to SOCK_CLOSED and according to the datasheet (page 47 in current 1.0.6) there is no interrupt. In my event based interrupt system I have a task blocking wait on CON and TIMEOUT. I can’t poll simultaneous the Sn_SR for SOCK_CLOSE because this would make the interrupt concept useless. For the CONNECT command polling the Sn_SR won’t be a big problem because my embedded systems won’t call this function very often. But as I understand RST packet can be received during communication all the time. Does this mean I have to check Sn_SR for SOCK_CLOSE although during waiting for SEND_OK/RECV interrupts? Thanks for any ideas.

bangbh · Answer

Hi, DevRX. I’m peter employee of wiznet. You’re right. There is no “closed” or “RST” interrupt on datasheet. We designed that disconnect interrupt occur after RST packet received. But it was not tested. Please check weather “disconnect” interrupt occur or not after RST packet received. Thanks.

avivf · Answer

Hello, Has anyone tested if “disconnect” interrupt occurs after RST packet was received? Can I assume that this interrupt is reliable? Thanks, Aviv