USB curosity

[Berend De Schouwer]

On Sun, 2015-12-13 at 19:23 -0800, Geoffrey Leach wrote:
> I have a LaserJet 1300 printer that connects via a Belkin parallel
> port-to-USB connector. When I send a document to the printer, half
> the time it prints without hesitation; other times it stalls until I
> disconnect and re-connect the USB cable. When I do that, here's what
> dmesg reports:

I've had some devices do that when they didn't get enough power over
USB.  Have you tried another USB port?  Do you have a powered USB hub?

> [80924.737154] usb 4-1.1: USB disconnect, device number 4
> [80924.737587] usblp0: removed
> [80926.381095] usb 4-1.1: new full-speed USB device number 5 using
> ehci-pci
> [80926.472738] usb 4-1.1: New USB device found, idVendor=050d,
> idProduct=0002
> [80926.472749] usb 4-1.1: New USB device strings: Mfr=1, Product=2,
> SerialNumber=0

The serial number shouldn't be zero.  Cups uses different serial
numbers do differentiate between printers.  It shouldn't be, but it can
be.

What's the cups device?  Are you using parallel://dev/lp0 or usb:// ?
 Might be something like
"usb://EPSON/Stylus%20Photo%20R200?serial=M02P20502230111234"

> [80926.472755] usb 4-1.1: Product: IEEE-1284 Controller
> [80926.472759] usb 4-1.1: Manufacturer: Belk USB Printing Support
> [80926.497804] usblp 4-1.1:1.0: usblp0: USB Bidirectional printer dev
> 5 if 0 alt 1 proto 2 vid 0x050D pid 0x0002
> 
> CUPS discovers the printer without any problems. However, when I send
> the test document from CUPS, no amount of fiddling with the USB cable
> will cause it to print.

Will "echo -en 'hello world\n\f' > /dev/usb/lp0" print?  This should
print the text, with a form feed.  I assume it will block (wait
forever)

The device might be /dev/usblp0 or /dev/usb/lp0.  There might be a
symbolic link /dev/lp0 -> /dev/usb/lp0.

> 
> Any insights will be greatly appreciated.
> 
> Firefox 23; kernel 4.2.6-301.fc23.x86_64 #1 SMP, everything up to
> date.