4.4. USB Devices
4.4.1. USB 1.1
Linux supports USB pretty well. USB should work with any late-model 2.2 kernel, and any 2.4 kernel or newer. Of course you need kernel support for USB, either linked in or through a module (recommended).
If you have a modular kernel, the following modules need to be loaded:
Which one of usb-uhci.o or uhci.o or usb-ohci.o you need depends on the kind of motherboard or adaptor you have. Intel and Via motherboards and Via based adaptors are UHCI (you can use either usb-uhci.o or uhci.o). You can find out which type of HCI (Host Controller Interface) you have with
lspci -v|grep HCI
4.4.3. Hints
One thing to remember is that USB devices are dynamically allocated. A USB printer gets assigned a device file (/dev/usb/lp*) when it is turned on or connected. This could mean that print jobs are sent to the wrong printer because you turned them on in a certain order. CUPS uses special Uri's containing manufacturer, model and printer serial number to keep sending the jobs to the correct physical printer.
Although most USB printers work fine on Linux, there are exceptions. For example the new MF devices from Epson (Stylus CX3200/CX5200) return garbage when one polls the IEEE-1284 ID string via IOCTL, for example
with the code of the CUPS "usb" backend. Whereas one can poll the ID string via an Epson-proprietary method.
Till Kamppeter has written some tools to retrieve the device ID string from USB printers. getusbprinterid.pl and usb_id_test.c are the same thing but respectively in Perl and C. As mentioned above, the new MF devices from Epson are an exception, but the "Epson proprietary method" is implemented in the ttink tool of the MTink package.
More documentation about USB is available at the Linux USB Website.
