[lwip-users] TCPIP and MAC thread task priorities

[Wayne Uroda]

I was looking through my codebase recently (a mix of code from LPC Open, and also a project I inherited) and I saw a comment which I want to fact check:

/* TCPIP thread must run at higher priority than MAC threads! */

My software is using FreeRTOS. The Ethernet interrupt only signals a semaphore which wakes up the "MAC" thread. This thread handles incoming and outgoing packets on the ethernet hardware.

The comment implies that this MAC thread must run at a lower priority than the TCPIP thread. I don't know who wrote the comment, or if it is correct.

This posting 

http://lists.nongnu.org/archive/html/lwip-users/2010-03/msg00148.html

indicates that there may not be such a stringent requirement, and it might even be advantageous to have the Ethernet task run at a higher priority than the TCPIP thread, but I'm not sure if the same applies to a MAC thread.

Thanks

- Wayne