alpine linux mdev cups

gistfile1.txt

# udevadm monitor                                   
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing 
KERNEL - the kernel uevent                                                                                            
                                                                                                                      
KERNEL[88431.251041] remove   /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0/usbmisc/lp0 (usbmisc)
KERNEL[88431.251089] remove   /usbmisc (class)                                                                        
KERNEL[88431.251127] unbind   /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0 (usb)
KERNEL[88431.251161] remove   /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0 (usb)
KERNEL[88431.251204] unbind   /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1 (usb)
KERNEL[88431.251246] remove   /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1 (usb)
KERNEL[88433.232085] add      /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1 (usb)
KERNEL[88433.232200] add      /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0 (usb)
KERNEL[88433.232443] add      /class/usbmisc (class)                                                                  
KERNEL[88433.232849] add      /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0/usbmisc/lp0 (usbmisc)         
KERNEL[88433.232890] bind     /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0 (usb)
KERNEL[88433.232933] bind     /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1 (usb)

# udevadm info --path /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1 
P: /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1
N: bus/usb/002/010
E: BUSNUM=002
E: DEVNAME=/dev/bus/usb/002/010
E: DEVNUM=010
E: DEVPATH=/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1
E: DEVTYPE=usb_device
E: DRIVER=usb
E: MAJOR=189
E: MINOR=137
E: PRODUCT=4b8/7/100
E: SUBSYSTEM=usb
E: TYPE=0/0/0

# cat /sys/kernel/debug/usb/devices | grep -E "^([TSPD]:.*|)$"

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480  MxCh= 2
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0002 Rev= 5.04
S:  Manufacturer=Linux 5.4.27-0-lts ehci_hcd
S:  Product=EHCI Host Controller
S:  SerialNumber=0000:00:1a.0

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480  MxCh= 6
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=8087 ProdID=0020 Rev= 0.00

T:  Bus=01 Lev=02 Prnt=02 Port=01 Cnt=01 Dev#=  3 Spd=12   MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0557 ProdID=2221 Rev= 0.01
S:  Manufacturer=Winbond Electronics Corp
S:  Product=Hermon USB hidmouse Device

T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480  MxCh= 2
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0002 Rev= 5.04
S:  Manufacturer=Linux 5.4.27-0-lts ehci_hcd
S:  Product=EHCI Host Controller
S:  SerialNumber=0000:00:1d.0

T:  Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480  MxCh= 8
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=8087 ProdID=0020 Rev= 0.00

T:  Bus=02 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 10 Spd=480  MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=04b8 ProdID=0007 Rev= 1.00
S:  Manufacturer=EPSON
S:  Product=USB2.0 Printer (Hi-speed)
S:  SerialNumber=55PKAZZ21175100705

# tail -n 1 /etc/mdev.conf 
SUBSYSTEM=usb;PRODUCT=4b8/7/100;.* root:lp 660 */lib/mdev/usbdev

## unplug and plug again

# ls -l /dev/bus/usb/002/*
crw-rw---- 1 root root 189, 128 Apr 14 19:10 /dev/bus/usb/002/001
crw-rw---- 1 root root 189, 129 Apr 14 19:16 /dev/bus/usb/002/002
crw-rw---- 1 root lp   189, 138 Apr 14 20:38 /dev/bus/usb/002/011

# lpinfo -v
network http
network ipp
network beh
network socket
network lpd
network https
network ipps
direct usb://EPSON/AL-M2000?serial=55PKAZZ21175100705