[systemd-devel] udev rules for MCS7715 USB-attached parallel port

[Alex Henrie]

2016-02-22 7:15 GMT-07:00 Lennart Poettering <lennart at poettering.net>:
> On Sun, 21.02.16 15:26, Alex Henrie (alexhenrie24 at gmail.com) wrote:
>
>> Hi,
>>
>> I recently bought an MCS7715 USB-attached parallel port,[1] but there
>> seem to be a couple of problems using it with Linux:
>>
>> 1. The lp, parport, and parport_pc kernel modules are not loaded when
>> the device is plugged in.
>
> AFAIK parport_pc is the driver for old built-in parallel ports, it
> it not used f you have a USB paralell port adapter.

OK. Still, at minimum lp needs to be loaded when the USB parallel port
adapter is plugged in.

>> 2. After manually loading the kernel modules, /dev/lp0 is not deleted
>> when the device is unplugged.
>
> /dev/lp0 is also the old built-in parallel port. USB printers and
> parallel ports show up as /dev/usb/lp0 or so..

When I plug in the device, /dev/lp0 appears; /dev/usb/lp0 does not.
Furthermore, when I unplug and plug it back in, /dev/lp1 appears
alongside /dev/lp0. A third time and I have /dev/lp0, /dev/lp1, and
/dev/lp2.

Are you sure that this is not a udev rules bug? If it isn't, where
should I report it?

-Alex