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I have a strange problem with my serial port. It seems that sth has changed after ubuntu actualizations and reboot.
przem@przem:~/Pulpit/bat/scripts$ python
Python 2.7.6 (default, Jun 22 2015, 17:58:13)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import serial
>>> ser = serial.Serial("/dev/ttyUSB0", 57600)
>>> ser.read()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/serial/serialposix.py", line 475, in read
raise SerialException('device reports readiness to read but returned no data (device disconnected or multiple access on port?)')
serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?)
>>>
I know that I should have ' ' (empty sign) result from my device but instead of it I get exception:
'device reports readiness to read but returned no data (device disconnected or multiple access on port?)'
This question is an introduction to my problem: https://stackoverflow.com/questions/32844942/serialport-doenst-work-correctly-after-ubuntu-update?noredirect=1#comment53527004_32844942
Please help me.
Thank you for your answer. I have reported it: https://bugs.launchpad.net/ubuntu/+source/python2.7/+bug/1501240
Is it possible to undo update?
You look into the update log in /var/log/apt/history.log. One of the packages in the last block must have caused the trouble. See here for reverting updates.
– Philipp R. – 2015-09-30T11:41:05.207Here is the list of last updates: http://snag.gy/Q55wX.jpg
I tried to revert lprevious libgudev-1.0.0 and gir1.2-gudev-10 but nothing changed. I don't know which update has influence on this serialport
Could be a kernel issue, see here: https://www.mail-archive.com/kernel-packages@lists.launchpad.net/msg137077.html
– Philipp R. – 2015-09-30T14:14:08.017Thank you so much. I have done downgrade and now is OK. solved! – pb. – 2015-10-01T14:43:29.823