Comment 9 for bug 1501345

I have found the "serial" library no longer works in Python.2.7. I discovered this when using Python to read and parse a serial stream from my Arduino Uno based weather station. The Arduino listens in on 433MHz signals from my Oregon Scientific weather station sensors and sends a stream of weather data every minute to the web server via a USB/Serial inerface. The web server has worked well with this system 24/7 for the last 5-6 years and suddenly it is broken on the upgrade to 3.13.0-65-generic kernel. Downgrading the Kernel to 3.13.0-63-generic has worked for me and also I am using Ubuntu 14.04.3 LTS as XUbuntu.

Whether it is a problem with Ubuntu or Python or Arduino, I don't know as the latter two may have problems with how the serial interface is initiated or maintained, and the Ubuntu may just have a higher specification now that they can't deal with.

However my Arduino IDE downloads programs and 'listens' to the serial stream from the Uno with 3.13.0-65-generic Ok, So my suspicions is the broken bit is between the kernel and Python???

Here is the Python error message-
Traceback (most recent call last):
  File "SerialDemo.py", line 19, in <module>
    dataIn = ser.readline()
  File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 460, in read
    raise SerialException('device reports readiness to read but returned no data (device disconnected?)')
serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected?)