kernel-packages team mailing list archive

[kerlyn <1501345@xxxxxxxxxxxxxxxxxx>]

I agree with @rob-gaddi, this appears to be a driver bug.  I am running
a C application called tunslip, which is provided as part of the Contiki
OS distro.  select() indicates there are bytes available on &rset even
when this is not the case.  A subsequent fread() on the serial device
returns zero bytes, resulting in an exception.

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https://bugs.launchpad.net/bugs/1501345

Title:
  linux-image-3.13.0-65-generic breaks serial communication

Status in linux-lts-trusty package in Ubuntu:
  Confirmed

Bug description:
  Today after updating to the linux-image-3.13.0-65-generic 3.13.0-65
  Kernel on Lubuntu 14.04.3 LTS two different programs that rely on
  PySerial quit working. miniterm.py and my ROS (Robot Operating System)
  based Python node quit working.

  When rebooted and selected 3.13.0-63-generic via GRUB everything
  worked again.

  Here are the steps to create the issue with miniterm.py, note that you
  need something connected via a USB to Serial adapter for this to work.
  I am working with a Parallax Activity Board, but an Arduino should
  also exhibit the same behavior.

  sudo apt install linux-image-3.13.0-65-generic
  sudo apt install linux-image-extra-3.13.0-65-generic
  reboot

   $ miniterm.py /dev/ttyUSB0 115200
  --- Miniterm on /dev/ttyUSB0: 115200,8,N,1 ---
  --- Quit: Ctrl+]  |  Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---

  --- exit ---
  Exception in thread Thread-1:
  Traceback (most recent call last):
    File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
      self.run()
    File "/usr/lib/python2.7/threading.py", line 763, in run
      self.__target(*self.__args, **self.__kwargs)
    File "/usr/bin/miniterm.py", line 220, in reader
      data = character(self.serial.read(1))
    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?)')
  SerialException: device reports readiness to read but returned no data (device disconnected?)

  Reverting to the 3.13.0-63 kernel allows miniterm.py and other Python
  Serial based programs to work normally.

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