Saya menggunakan sejumlah adapter USB-to-serial yang identik dengan laptop saya (Ubuntu 9.10). Adaptor diproduksi oleh Sabrent dan dibangun di sekitar IC PL2303 Prolific, seperti yang ditunjukkan oleh lsusb
:
Bus 001 Device 008: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 001 Device 007: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 001 Device 006: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Tak satu pun dari atribut yang ditampilkan udevadm
tampaknya unik untuk adaptor tertentu:
foo@bar:~$ udevadm info --attribute-walk --path=/sys/bus/usb-serial/devices/ttyUSB0
looking at device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4.1/1-4.1:1.0/ttyUSB0':
KERNEL=="ttyUSB0"
SUBSYSTEM=="usb-serial"
DRIVER=="pl2303"
ATTR{port_number}=="0"
looking at parent device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4.1/1-4.1:1.0':
KERNELS=="1-4.1:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="pl2303"
ATTRS{bInterfaceNumber}=="00"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bNumEndpoints}=="03"
ATTRS{bInterfaceClass}=="ff"
ATTRS{bInterfaceSubClass}=="00"
ATTRS{bInterfaceProtocol}=="00"
ATTRS{modalias}=="usb:v067Bp2303d0300dc00dsc00dp00icFFisc00ip00"
ATTRS{supports_autosuspend}=="1"
looking at parent device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4.1':
KERNELS=="1-4.1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="80"
ATTRS{bMaxPower}=="100mA"
ATTRS{urbnum}=="538"
ATTRS{idVendor}=="067b"
ATTRS{idProduct}=="2303"
ATTRS{bcdDevice}=="0300"
ATTRS{bDeviceClass}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="12"
ATTRS{busnum}=="1"
ATTRS{devnum}=="6"
ATTRS{version}==" 1.10"
ATTRS{maxchild}=="0"
ATTRS{quirks}=="0x0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="Prolific Technology Inc."
ATTRS{product}=="USB-Serial Controller"
<snip>
foo@bar:~$ udevadm info --attribute-walk --path=/sys/bus/usb-serial/devices/ttyUSB1
looking at device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4.5/1-4.5:1.0/ttyUSB1':
KERNEL=="ttyUSB1"
SUBSYSTEM=="usb-serial"
DRIVER=="pl2303"
ATTR{port_number}=="0"
looking at parent device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4.5/1-4.5:1.0':
KERNELS=="1-4.5:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="pl2303"
ATTRS{bInterfaceNumber}=="00"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bNumEndpoints}=="03"
ATTRS{bInterfaceClass}=="ff"
ATTRS{bInterfaceSubClass}=="00"
ATTRS{bInterfaceProtocol}=="00"
ATTRS{modalias}=="usb:v067Bp2303d0300dc00dsc00dp00icFFisc00ip00"
ATTRS{supports_autosuspend}=="1"
looking at parent device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-4/1-4.5':
KERNELS=="1-4.5"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="80"
ATTRS{bMaxPower}=="100mA"
ATTRS{urbnum}=="69"
ATTRS{idVendor}=="067b"
ATTRS{idProduct}=="2303"
ATTRS{bcdDevice}=="0300"
ATTRS{bDeviceClass}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="12"
ATTRS{busnum}=="1"
ATTRS{devnum}=="7"
ATTRS{version}==" 1.10"
ATTRS{maxchild}=="0"
ATTRS{quirks}=="0x0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="Prolific Technology Inc."
ATTRS{product}=="USB-Serial Controller"
<snip>
Semua adapter dicolokkan ke hub USB tunggal. Karena saya tidak dapat membedakan antara adaptor itu sendiri, adakah yang bisa saya tuliskan aturan udev yang menetapkan nama setiap adaptor berdasarkan pada port fisik mana pada hub yang dihubungkan adaptor itu?