On 14.08.2025 7:40 PM, Alan Stern wrote:
Yes, but I can't imagine why delays would cause a NOTREADY, OFFLINE, or UNDERFLOW error.
The laser printers roll the paper with the constant speed, they don't slow down when they have insufficient data.
If the host doesn't send the image data in time (and here it happens during the print of a single page just as it rolls, as it is too large to fit into the printer's RAM), the job is marked as failed due to underflow of print data.
It's similar to CnC device in that sense. Modern printers wait for the full page, but this printer is from the era when RAM was expensive and could not (reliably) fit the whole page.
Either .pcap files or the usbmon text output for both of these tests would be good. But set the number of iterations to something very small, like 10 or so. No point posting a log containing thousands of repetitions of the same information...
Here you are, check the attachment. It's a 30 times loop.Also tried the speedtest.py on an old HP T510 thin client (x86, VIA chipset, UHCI), and the speeds are fine.
Avg delta: 0.990 ms Min: 0.870 ms Max: 1.984 ms My guess it's OHCI to blame.
<<attachment: usb11-usb20-capture.zip>>
