HPLIP ugen

[Stefan Esser]

Lars Eighner wrote:
> On Sat, 1 Sep 2007, Brian Wagener wrote:
> 
>> When using HPLIP your usb printer has to use the ugen driver in order for
>> all printing/scanning/status functionality to be present. The problem
>> is, my
>> printer loads as a umass device so it doesn't get detected by hplip.
>>
>> Does anyone know of a workaround for this? Is there anyway to force my
>> printer to use ugen instead of umass? I can't just remove umass because
>> other devices require it.
> 
> The only way is to use a kernel built without umass (and without ulpt).  If
> you can boot without umass, you can load umass from the command line (using
> kldload) after the printer is attached.  Although I have not actually tried

Hmmm, there might be two methods to implement a more user-
friendly behaviour:

1) Make umass ignore the device

2) Make ugen accept it with higher priority than umass

For 1) the umass driver should get a "DONOTATTACH" quirk,
which then lets ugen gain control. But if anybody wanted
to use the umass driver with that printer (e.g. if he is
only interested in reading from the built-in card reader
and does not want to print anything), this would not be
possible (without installation of HPLIP, that is).
If the device was grabbed by ulpt (if umass does not want
it, then it must be black-listed in both, but I do not
expect this to be the case).

Variant 2) would need a device table and support for
scanning it to be added to ugen. Devices that are best
served by ugen could be entered to that list, to prevent
other drivers from taking precedence. This does not seem
such an uncommon situation and might also be useful for
device protocol tests, for example. Device hints could
be used to control this feature for specific devices.

Either variant is workable (but 1) is easier to implement).
It may be counter-intuitive for a device to be added to a
driver that is *not* meant to be used to control it ...

Regards, STefan