Description of problem: Version-Release number of selected component (if applicable): FC6 Gold, Cups How reproducible: Steps to Reproduce: 1. Plug into USB port a USB<->Serial dongle 2. It appears as /dev/ttyUSB0 (if it was the 1st one) 3. Plug in a Serial printer to dongle Actual results: Trying to set up the printer via Printers menu item does not show up USB port nor USB/Serial. Expected results: Printers should have given the option to add a printer on a port /dev/ttyUSB0 manually. That would have solved the problem. What remains is how to set the speed of the serial link via a USB port. Additional info:
For reference: cups-1.2.4-9 Upstream bug report with patch: http://cups.org/str.php?L2061
Fixed in update: cups-1.2.5-2.fc6.8
Just tested and this time the USB-Serial dongle was detected correctly as /dev/ttyUSB0. I was able to set up the printer. The printer is a Zebra Cameo 3 label printer and it expects the serial port to be 19200, 8N1 with Xon/Xoff/Hardware and DSR=0. I tried all the options in the system-config-printer GUI. When the printer options are changed around, and the check box "Enabled" under the Settings tab is checed ON, then the lpq says that the printer is ready. The GUI says that it is idle. Sending out a test page - nothing happens. lpq shows it in the queue. When the test page was sent, the lpq status showed that it was ready and printing and then goes into a "zebra is not ready" state. Removing the queue entry with lprm queue#, the lpq still returns the state the the "zebra is not ready". Now restarting the GUI, I notice that the printer (under Settings tab) show the "Enabled" check box unchecked. Not sure why that happens for I had checked it before exiting the GUI. I tried with minicom and connected to /dev/ttyUSB0 directly (with 192008N1) and I was able to echo characters on the printer. What else can I try?
Does /var/log/cups/error_log show why the job failed?
Yes, it does. Apologies for not checking that. It said that there was no permission to write to /dev/ttyUSB0. The default ownership and rw status when the dongle is plugged in is: crw-rw---- 1 root uucp 188, 0 Nov 21 20:00 /dev/ttyUSB0 I had to change the rw to: crw-rw-rw- 1 root uucp 188, 0 Nov 21 20:00 /dev/ttyUSB0 before the printing was successful. Not sure where I need to set up the right permissions to kick in when the USB dongle is plugged in. Thanks for the tip.
cups-1.2.7-1.2.fc6 from updates-testing should fix it. It makes the serial backend run as root. It doesn't seem to have been pushed yet, but will be in the next couple of days I expect.