Udevinfo 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/pci0000:00/0000:00:1d.7/usb8/8-4/8-4:1.1/tty/ttyACM0':
    KERNEL=="ttyACM0"
    SUBSYSTEM=="tty"
    DRIVER==""

  looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb8/8-4/8-4:1.1/tty':
    KERNELS=="tty"
    SUBSYSTEMS==""
    DRIVERS==""

  looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb8/8-4/8-4:1.1':
    KERNELS=="8-4:1.1"
    SUBSYSTEMS=="usb"
    DRIVERS=="cdc_acm"
    ATTRS{bInterfaceNumber}=="01"
    ATTRS{bAlternateSetting}==" 0"
    ATTRS{bNumEndpoints}=="01"
    ATTRS{bInterfaceClass}=="02"
    ATTRS{bInterfaceSubClass}=="02"
    ATTRS{bInterfaceProtocol}=="01"
    ATTRS{modalias}=="usb:v0BDBp1900d0000dc02dsc00dp00ic02isc02ip01"
    ATTRS{interface}=="Ericsson F3507g Mobile Broadband Minicard Modem"
    ATTRS{bmCapabilities}=="7"

  looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb8/8-4':
    KERNELS=="8-4"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{configuration}=="WMC Device"
    ATTRS{bNumInterfaces}=="11"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bmAttributes}=="e0"
    ATTRS{bMaxPower}==" 20mA"
    ATTRS{urbnum}=="679"
    ATTRS{idVendor}=="0bdb"
    ATTRS{idProduct}=="1900"
    ATTRS{bcdDevice}=="0000"
    ATTRS{bDeviceClass}=="02"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{bNumConfigurations}=="2"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{speed}=="480"
    ATTRS{busnum}=="8"
    ATTRS{devnum}=="3"
    ATTRS{version}==" 2.00"
    ATTRS{maxchild}=="0"
    ATTRS{quirks}=="0x0"
    ATTRS{authorized}=="1"
    ATTRS{manufacturer}=="Ericsson"
    ATTRS{product}=="Ericsson F3507g Mobile Broadband Minicard Composite Device"
    ATTRS{serial}=="3541430206062990"

  looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb8':
    KERNELS=="usb8"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{configuration}==""
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bmAttributes}=="e0"
    ATTRS{bMaxPower}=="  0mA"
    ATTRS{urbnum}=="40"
    ATTRS{idVendor}=="1d6b"
    ATTRS{idProduct}=="0002"
    ATTRS{bcdDevice}=="0206"
    ATTRS{bDeviceClass}=="09"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{speed}=="480"
    ATTRS{busnum}=="8"
    ATTRS{devnum}=="1"
    ATTRS{version}==" 2.00"
    ATTRS{maxchild}=="6"
    ATTRS{quirks}=="0x0"
    ATTRS{authorized}=="1"
    ATTRS{manufacturer}=="Linux 2.6.27-7-generic ehci_hcd"
    ATTRS{product}=="EHCI Host Controller"
    ATTRS{serial}=="0000:00:1d.7"
    ATTRS{authorized_default}=="1"

  looking at parent device '/devices/pci0000:00/0000:00:1d.7':
    KERNELS=="0000:00:1d.7"
    SUBSYSTEMS=="pci"
    DRIVERS=="ehci_hcd"
    ATTRS{vendor}=="0x8086"
    ATTRS{device}=="0x293a"
    ATTRS{subsystem_vendor}=="0x17aa"
    ATTRS{subsystem_device}=="0x20f1"
    ATTRS{class}=="0x0c0320"
    ATTRS{irq}=="19"
    ATTRS{local_cpus}=="ffffffff,ffffffff"
    ATTRS{local_cpulist}=="0-63"
    ATTRS{modalias}=="pci:v00008086d0000293Asv000017AAsd000020F1bc0Csc03i20"
    ATTRS{broken_parity_status}=="0"
    ATTRS{msi_bus}==""

  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""