Created attachment 280269 [details]
.config_4.20

BUG IN 4.18.5 and newest.
_________________________
ANNOTATION.

KERNEL 4.20.0 BASIC CONFIGURATION.
CONFIGURED BY GENKERNEL.

1) COMPUTER NOT HAVE POWER.
2) CONNECT USB PRINTER.
3) POWER ON COMPUTER AND BOOT SYSTEM SUCCESEFULL.
4) OPEN 127.0.0.1:631/OR LOCALHOST:631
5) ADD PRINTER 
6) PRINTER SEARCHED AND CAN BE ATTACHED. (in dmesg lines NEW DEVICE PRINTER blablabla... usblp0)

7!) UNPLUG PRINTER
8!) CONNECT PRINTER TO USB
9!) OPEN 127.0.0.1:631/OR LOCALHOST:631
10!) CLICK ADD PRINTER 
11!) !!!USB PRINTER NOT FOUND!!!
12!) open dmesg and i see line NEW DEVICE PRINTER blablabla usblp0
13!) CANNOT ADD PRINTER OR BEFORE ADDING PRINTER NOT WORK.

AFTER REBOOT, PRINTER WORK AND SOLVE PRINT TASKS, BUT IF PRINTER LOST USB CONNECTION, PRINTER CUPS NOT SEE AND NOT WORK WITH PRINTER.
________________________________
KERNEL 4.4.40
IN KERNEL 4.4.40 IF I RECONNECT PRINTER, PRINTER GOOD WORK.
_________________________________
IN WINDOWS 7 and later printer work good, and work good in virtual machine QEMU +libvirt.  IF in 4.20.0 cups not see and canot work with printer and i redirect printer to virtual machine printer good work.
________________________________
ITS BUG IN KERNEL OR IN PRINTER SUBSYSTEM OR CUPS AND KERNEL VERSION DEFINED PROBLEM.
________________________________
BUG PLATFORM/HARDWARE INDEPENDED, bug can be listen on ASUS exteme 4 motherboard i7 3770k, USB2/3, and newest ASUS GL703VD laptop.