Serial (RS-232) Interface Not Working Properly in Linux Mint 17.3 Cinnamon

[Richard Olsen]

I have a GUI application that interfaces with a micro-controller through RS-232. However, in Linux Mint 17.3 it no longer works properly. It has been working correctly since Ubuntu 8.04 and up through Debian (the current version), Ubuntu 15.04 and Linux Mint 17.2.

The sequence of events are:
  1) The device is opened and the first command is sent to the micro and the response is correct.
  2) For each command send thereafter, (generally) the first response byte is received but the rest of the information is lost. On occasion, the first byte is lost and the remainder of the response is received. There are occasions where the remainder of the response for one command is received after a different command has been sent. Under no conditions (that I have seen) has the response been different than the first byte being received and the remainder of the response lost, or the first byte lost and the remainder of the response received.

If I use a USB to RS-232 interface, then the application also works correctly in Linux Mint 17.3 (different drivers obviously).

As stated above, only Linux Mint 17.3 has this problem and it occurs in both the 32 bit and 64 bit versions.

[Richard Olsen (olsenra)]

This may be an issue with setserial (or how I am using it). Before running the application, I use setserial like this:
    sudo setserial /dev/ttyS1 port 0x1018 UART 16550A irq 17 Baud_base 115200
While this worked in the past, I may now need to do something different (but I don't know what).