Intermittent drop of Ethernet transmit packets

[element]

Posted on January 28, 2016 at 22:00The original post was too long to process during our migration. Please click on the attachment to read the original post.

[element]

Posted on January 29, 2016 at 07:48

I resolved a couple of issues which were affecting this problem and I wanted to follow up for anyone who comes upon this thread.

After logging the transmit descriptor status word value I discovered that collisions were occurring when packets were being dropped and that re-transmit was disabled.  Enabling re-transmit fixed the problem.In addition I found that the the PHY_SR define in stm32_eth.h (from some reference source code) is PHY specific.  It was incorrect for the PHY I am using, so the duplex state was incorrect (thought it was half duplex, when in fact it was full duplex).  I just had to update the register, PHY_Speed_Status, and PHY_Duplex_Status defines to match that of the LAN8720A.Best regards,Element