Thank you for the tests. They show that it does not matter whether you use the old method of the "usblp" kernel module or the new method of using libusb to print. The timing issue occurs with both methods.
This still does not say whether the culprit is the kernel or the filter/driver chain. The USB CUPS backend is less probable as the problem is also triggered by a print queue pointing to file:/dev/usb/lp0. This queue does not use the USB CUPS backend but the filter/driver chain and the kernel are still used.
If the printer worked correctly under Ubuntu 11.04 or 10.10, the problem is most probably a kernel problem as the filter chains of 11.04 and 10.10 were significantly slower than of 11.10.
Thank you for the tests. They show that it does not matter whether you use the old method of the "usblp" kernel module or the new method of using libusb to print. The timing issue occurs with both methods.
This still does not say whether the culprit is the kernel or the filter/driver chain. The USB CUPS backend is less probable as the problem is also triggered by a print queue pointing to file:/dev/usb/lp0. This queue does not use the USB CUPS backend but the filter/driver chain and the kernel are still used.
If the printer worked correctly under Ubuntu 11.04 or 10.10, the problem is most probably a kernel problem as the filter chains of 11.04 and 10.10 were significantly slower than of 11.10.