Important notes about our chip.
$ sudo lsusb Bus 002 Device 002: ID 0bda:5411 Realtek Semiconductor Corp. Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:07dc Intel Corp. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub ... Bus 002 Device 005: ID 10c4:ea60 Cygnal Integrated Products, Inc. CP210x UART Bridge / myAVR mySmartUSB light $ sudo lsusb -v -s 002:005
And from sudo lsusb -v -s 002:005
$ sudo lsusb -v -s 004:006 Bus 002 Device 005: ID 10c4:ea60 Cygnal Integrated Products, Inc. CP210x UART Bridge / myAVR mySmartUSB light Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x10c4 Cygnal Integrated Products, Inc. idProduct 0xea60 CP210x UART Bridge / myAVR mySmartUSB light bcdDevice 1.00 iManufacturer 1 iProduct 2 iSerial 3 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 32 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 100mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 2 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Device Status: 0x80 (Bus Powered)
$ sudo udevadm info -a -n /dev/ttyUSB0 Udevadm info starts with the device specified by the devpath and then walks up the chain of parent devices. It prints for every device found, all possible attributes in the udev rules key format. A rule to match, can be composed by the attributes of the device and the attributes from one single parent device. looking at device '/devices/platform/tegra-ehci.2/usb2/2-1/2-1.1/2-1.1:1.0/ttyUSB0/tty/ttyUSB0': KERNEL=="ttyUSB0" SUBSYSTEM=="tty" DRIVER=="" looking at parent device '/devices/platform/tegra-ehci.2/usb2/2-1/2-1.1/2-1.1:1.0/ttyUSB0': KERNELS=="ttyUSB0" SUBSYSTEMS=="usb-serial" DRIVERS=="cp210x" ATTRS{port_number}=="0" looking at parent device '/devices/platform/tegra-ehci.2/usb2/2-1/2-1.1/2-1.1:1.0': KERNELS=="2-1.1:1.0" SUBSYSTEMS=="usb" DRIVERS=="cp210x" ATTRS{bInterfaceClass}=="ff" ATTRS{bInterfaceSubClass}=="00" ATTRS{bInterfaceProtocol}=="00" ATTRS{bNumEndpoints}=="02" ATTRS{supports_autosuspend}=="1" ATTRS{bAlternateSetting}==" 0" ATTRS{bInterfaceNumber}=="00" ATTRS{interface}=="CP2102 USB to UART Bridge Controller" looking at parent device '/devices/platform/tegra-ehci.2/usb2/2-1/2-1.1': KERNELS=="2-1.1" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="00" ATTRS{devpath}=="1.1" ATTRS{idVendor}=="10c4" ATTRS{speed}=="12" ATTRS{bNumInterfaces}==" 1" ATTRS{bConfigurationValue}=="1" ATTRS{bMaxPacketSize0}=="64" ATTRS{busnum}=="2" ATTRS{devnum}=="5" ATTRS{configuration}=="" ATTRS{bMaxPower}=="100mA" ATTRS{authorized}=="1" ATTRS{bmAttributes}=="80" ATTRS{bNumConfigurations}=="1" ATTRS{maxchild}=="0" ATTRS{bcdDevice}=="0100" ATTRS{avoid_reset_quirk}=="0" ATTRS{quirks}=="0x0" ATTRS{serial}=="0001" ATTRS{version}==" 1.10" ATTRS{urbnum}=="17" ATTRS{ltm_capable}=="no" ATTRS{manufacturer}=="Silicon Labs" ATTRS{removable}=="unknown" ATTRS{idProduct}=="ea60" ATTRS{bDeviceClass}=="00" ATTRS{product}=="CP2102 USB to UART Bridge Controller" looking at parent device '/devices/platform/tegra-ehci.2/usb2/2-1': KERNELS=="2-1" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="02" ATTRS{devpath}=="1" ATTRS{idVendor}=="0bda" ATTRS{speed}=="480" ATTRS{bNumInterfaces}==" 1" ATTRS{bConfigurationValue}=="1" ATTRS{bMaxPacketSize0}=="64" ATTRS{busnum}=="2" ATTRS{devnum}=="2" ATTRS{configuration}=="" ATTRS{bMaxPower}=="0mA" ATTRS{authorized}=="1" ATTRS{bmAttributes}=="e0" ATTRS{bNumConfigurations}=="1" ATTRS{maxchild}=="4" ATTRS{bcdDevice}=="0104" ATTRS{avoid_reset_quirk}=="0" ATTRS{quirks}=="0x0" ATTRS{version}==" 2.00" ATTRS{urbnum}=="74" ATTRS{ltm_capable}=="no" ATTRS{manufacturer}=="Generic" ATTRS{removable}=="unknown" ATTRS{idProduct}=="5411" ATTRS{bDeviceClass}=="09" ATTRS{product}=="4-Port USB 2.0 Hub" looking at parent device '/devices/platform/tegra-ehci.2/usb2': KERNELS=="usb2" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{bDeviceSubClass}=="00" ATTRS{bDeviceProtocol}=="01" ATTRS{devpath}=="0" ATTRS{idVendor}=="1d6b" ATTRS{speed}=="480" ATTRS{bNumInterfaces}==" 1" ATTRS{bConfigurationValue}=="1" ATTRS{bMaxPacketSize0}=="64" ATTRS{authorized_default}=="1" ATTRS{busnum}=="2" ATTRS{devnum}=="1" ATTRS{configuration}=="" ATTRS{bMaxPower}=="0mA" ATTRS{authorized}=="1" ATTRS{bmAttributes}=="e0" ATTRS{bNumConfigurations}=="1" ATTRS{maxchild}=="1" ATTRS{bcdDevice}=="0310" ATTRS{avoid_reset_quirk}=="0" ATTRS{quirks}=="0x0" ATTRS{serial}=="tegra-ehci.2" ATTRS{version}==" 2.00" ATTRS{urbnum}=="19" ATTRS{ltm_capable}=="no" ATTRS{manufacturer}=="Linux 3.10.40-grinch-21.3.4 ehci_hcd" ATTRS{removable}=="unknown" ATTRS{idProduct}=="0002" ATTRS{bDeviceClass}=="09" ATTRS{product}=="Tegra EHCI Host Controller" looking at parent device '/devices/platform/tegra-ehci.2': KERNELS=="tegra-ehci.2" SUBSYSTEMS=="platform" DRIVERS=="tegra-ehci" ATTRS{boost_enable}=="Y" ATTRS{uframe_periodic_max}=="-1060791588" looking at parent device '/devices/platform': KERNELS=="platform" SUBSYSTEMS=="" DRIVERS==""