Fedora seems to lose track of attached printers when a laptop is undocked. I can consistently replicate this behavior. This printer is attached using a parallel port on the docking station. Steps to Reproduce: 1. Turn on laptop 2. Close screen and undock laptop 3. Open screen to revive laptop 4. Close screen and dock laptop 5. Open screen and print anything 6. Observe message about missing printer Additional info: If I reboot with the failed print job in the queue, the job begins to print *before* login.
Could you run "su -c 'dmesg -c'" at each stage and note what it says? This will show the kernel messages caused by each action.
Created attachment 663266 [details] 'dmesg -c' after undocking and resume
Created attachment 663267 [details] 'dmesg -c' after docking and resume
At step 5, before printing something, could you please run this command?: su -c 'lpinfo --include-schemes=parallel -v' What output, if any, do you get? Also of interest is the output of this command: su -c 'strace /usr/lib/cups/backend/parallel' 2>&1
# lpinfo --include-schemes=parallel -v direct parallel:/dev/lp0
Created attachment 666195 [details] strace /usr/lib/cups/backend/parallel 2>&1 strace.txt
Removing the 'private' flag as I don't see any private info in comments or attachments.
What exactly does the message about a missing printer say? When you see this message, it would be useful to run strace on the running 'parallel' process. Run 'ps axf' and look for the 'parallel://...' process that has been run by cupsd. Note the process ID (first column), then run: strace -p the-id-you-noted 2>strace.txt Leave it for, say, two minutes. Then press Control-C to stop the strace process, and attach strace.txt here. Thanks.
Okay, I'm not sure what changed or if those commands forced something but it works okay now.