Have to restart hp deskjet 3745 after lprm during print job

[lupv]

I am using Ubuntu 8.04, hp deskjet 3745. If I cancel a print job (with lprm) while the printer is printing, the paper stays in roller and the power light keeps flashing. I have to unplug the printer before can print again. In Windows if I can cancel a print job while it's printing, the paper gets rolled out completely and I can continue printing. Can I get the same thing going in ubuntu?

[David Suffield (david-suffield)]

The canceled print job may hang or not finish, but the next print job will clear any canceled print job and print correctly. This how the current hplip driver is designed to work.

Yes, this is different than Windows.

-dave

[lupv (lupv)]

As the power light keeps on flashing, I am unable to turn off the printer (e.g. to save energy) and have to unplug it at the back in order to stop the flashing. Then when I plug it back it, the flashing has stopped and I can turn it off again. This just occurred today, after cancelling a print job and having no more printing to do.

[lupv (lupv)]

Also, it is not entirely accurate that the "next print job will clear any canceled print job and print correctly". Although the next print job does go through, I have seen part of the canceled print job (it seems the part of the print job that was sent to the printer before being canceled) gets printed before it so I end up wasting one page of paper. This is a bug.

That is why it's best to unplug and then replug the printer before printing the next print job, not just to stop the flashing but to clear the canceled print job.

[David Suffield (david-suffield)]

Yes, that would be expected behavior there will be wasted paper. If you cancel a print job mid stream, the cancel will not delete data that is already down-stream in the printer. Inkjets have a limited buffer so they start printing as soon as they receive data.

[lupv (lupv)]

 "Inkjets have a limited buffer so they start printing as soon as they receive data." To clarify, it does not start printing this data once the job has been canceled. Only if you print another print job without unplugging the printer first, which as stated, is also the only way to stop the power light flashing and allow you to once again use the power button to power off the printer.

It would be helpful to design hplip such that this does not happen.

[lupv (lupv)]

So in other words, it is not quite accurate that the inkjets "start printing as soon as they receive data". The inkjet buffer holds onto remaining data of the cancelled print job until the next print job. It is not cleared from the buffer and is then printed at the beginning of the next print job.

[lupv (lupv)]

To summarize, I was NOT writing about what happens during the canceling of the print job but what happens AFTER a canceled print job has STOPPED PRINTING. Yes I know that paper can be wasted when you cancel a job mid-stream. I am not that ignorant! :). The issue is that it is NOT the "expected behavior" that some time later, when printing the NEXT print job, to still have part of the canceled job printing out at the beginning of the print job after the canceled job has been stopped for some time.

This may be why the power light keeps on flashing. Normally, with paper jams, out of paper, etc. the power light will also keep on flashing until you put in more paper, unstuck the paper, etc. and then you can press the power button to stop the flashing and resume printing. Here, part of the canceled print job is still in the queue and you cannot resume by pressing the power button. It can only stop flashing after unplugging or after you have sent ANOTHER print job. But then part of the canceled job is printed out on NEXT print job, as stated above. So you can waste paper TWICE, both during the canceling and again with the NEXT print job.

I have NEVER seen this behavior with other printers I have used i.e. that you have to unplug it in order to completely clear out a canceled print job that has already STOPPED PRINTING. That is, to prevent part of the canceled printing coming out the NEXT time you print and enable again turning off the printer by pressing the power button. These are two aspects of the same bug.

[lupv (lupv)]

And I got this bug even when there is no paper staying in the roller after a cancellation. I still saw one page of the canceled job partly print out as the beginning of the NEXT print job when I did not unplug the printer to stop the flashing in the power button before printing again.