Hi all, I'm working with a custom stm32f767 based board and px4 project fork with nuttx-10.0.0+ and uploading data (~900KB) to the board using mavlink_ftp.
If mavlink is over serial port everything is fine and long transfer going uninterruptedly, but if mavlink is over UDP link the ftp file transfer sometimes stumbles: PC doesn't receive acknowledgment, wait for timeout, retry request and continue to transfer normally some time until next stumble. According to mavlink_ftp debug, at that moment the board doesn't receive the last ftp mavlink package, so it doesn't send ack. I've checked with wireshark, a PC definitely sends a UDP packet out, but the board doesn't receive this mavlink packet. I can reproduce this issue easily, but didn't notice any regularity in the size of data between losses. When I've added DEBUG_FEATURES, DEBUG_ERROR, DEBUG_NET, DEBUG_NET_ERROR to config I can't reproduce the issue, no loss in UDP transfer. Mavlink FTP upload is quite simple: on each request there is the acknowledgement, no burst sending, so, as I see it, the issue should not be related to buffer overflow. Any thoughts on how to debug this or maybe someone remember potentially related fixes in UDP/Ethernet in recent NuttX? Thanks in advance for help! --- With best regards, Oleg.
