When I tried to set up an old usb printer, I was puzzled why I
couldn't print. I remember setting up
this printer using lpd with no difficulty under OpenBSD 5.9 using a
printcap entry similar to this.
lp|local line printer|hp|HP Deskjet 3050:\
:lp=/dev/ulpt0:sd=/var/spool/output/lpd:lf=/var/log/lpd-errs:
After some frustration, I noticed any attempt to print resulted in a
dmesg line, "xhci0: NULL xfer pointer".
Any write to the device file (like cat file >/dev/ulpt0) seems to trigger it.
The relevant dmesg lines are included below.
ulpt0 at uhub0 port 10 configuration 1 interface 1 "HP Deskjet 3050
J610 series" rev 2.00/1.00 addr 6
ulpt0: using bi-directional mode
ugen0 at uhub0 port 10 configuration 1 "HP Deskjet 3050 J610 series"
rev 2.00/1.00 addr 6
xhci0: NULL xfer pointer
Sincerely,
Colton Lewis
