This is an old thread that also pertains to creating udev rules for
various plug and play devices, particularly USB. Everything has been
working nicely for a few months under Ubuntu 10.04 but today for the
first time I tried to set up a pair of udev rules for two devices of the
same type that differ only in their serial numbers
The two devices are a pair of USB2Dynamixel controllers and the rules I
tried are:
# The USB2Dynamixel on Pi Robot controlling AX-12 servos
SUBSYSTEMS=="usb", KERNEL=="ttyUSB[0-9]*", ATTRS{manufacturer}=="FTDI",
ATTRS{product}=="FT232R USB UART", ATTRS{serial}=="A1001a6n",
SYMLINK+="usb2dynamixel12"
# The other USB2Dynamixel on Pi Robot controlling RX-24 servos
SUBSYSTEMS=="usb", KERNEL=="ttyUSB[0-9]*", ATTRS{manufacturer}=="FTDI",
ATTRS{product}=="FT232R USB UART", ATTRS{serial}=="A600cB3f",
SYMLINK+="usb2dynamixel24"
The trouble is that whenever I plug in either controller, *both* devices
get created (/dev/usb2dynamixel12 and /dev/usb2dynamixel24) and they
both point to the same /dev/ttyUSB device which is /dev/ttyUSB0 if only
one controller is plugged in and /dev/ttyUSB1 if they are both plugged in.
When I run
$ udevadm info -q all --attribute-walk -n /dev/ttyUSB0
when one or the other controller is plugged in, then diff the results I get:
54c54
< ATTRS{devnum}=="7"
---
> ATTRS{devnum}=="8"
61c61
< ATTRS{serial}=="A1001a6n"
---
> ATTRS{serial}=="A600cB3f"
72c72
< ATTRS{urbnum}=="85"
---
> ATTRS{urbnum}=="113"
99c99
< ATTRS{urbnum}=="57"
---
> ATTRS{urbnum}=="62"
so you can see my serial numbers are correct. Does anyone know how to
handle this situation?
Thanks!
patrick
http://www.pirobot.org
P.S. I have attached the entire output from udevadm when one of the
controllers is plugged in.
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/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.1/1-1.1.2/1-1.1.2:1.0/ttyUSB0/tty/ttyUSB0':
KERNEL=="ttyUSB0"
SUBSYSTEM=="tty"
DRIVER==""
looking at parent device '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.1/1-1.1.2/1-1.1.2:1.0/ttyUSB0':
KERNELS=="ttyUSB0"
SUBSYSTEMS=="usb-serial"
DRIVERS=="ftdi_sio"
ATTRS{latency_timer}=="1"
ATTRS{port_number}=="0"
looking at parent device '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.1/1-1.1.2/1-1.1.2:1.0':
KERNELS=="1-1.1.2:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="ftdi_sio"
ATTRS{bInterfaceNumber}=="00"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bNumEndpoints}=="02"
ATTRS{bInterfaceClass}=="ff"
ATTRS{bInterfaceSubClass}=="ff"
ATTRS{bInterfaceProtocol}=="ff"
ATTRS{modalias}=="usb:v0403p6001d0600dc00dsc00dp00icFFiscFFipFF"
ATTRS{supports_autosuspend}=="0"
ATTRS{interface}=="FT232R USB UART"
looking at parent device '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.1/1-1.1.2':
KERNELS=="1-1.1.2"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="a0"
ATTRS{bMaxPower}==" 90mA"
ATTRS{urbnum}=="15"
ATTRS{idVendor}=="0403"
ATTRS{idProduct}=="6001"
ATTRS{bcdDevice}=="0600"
ATTRS{bDeviceClass}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="8"
ATTRS{speed}=="12"
ATTRS{busnum}=="1"
ATTRS{devnum}=="7"
ATTRS{version}==" 2.00"
ATTRS{maxchild}=="0"
ATTRS{quirks}=="0x0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="FTDI"
ATTRS{product}=="FT232R USB UART"
ATTRS{serial}=="A1001a6n"
looking at parent device '/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.1':
KERNELS=="1-1.1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bMaxPower}=="100mA"
ATTRS{urbnum}=="85"
ATTRS{idVendor}=="05e3"
ATTRS{idProduct}=="0606"
ATTRS{bcdDevice}=="0702"
ATTRS{bDeviceClass}=="09"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="01"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="480"
ATTRS{busnum}=="1"
ATTRS{devnum}=="4"
ATTRS{version}==" 2.00"
ATTRS{maxchild}=="4"
ATTRS{quirks}=="0x0"
ATTRS{authorized}=="1"
ATTRS{product}=="USB2.0 Hub"
looking at parent device '/devices/pci0000:00/0000:00:1a.0/usb1/1-1':
KERNELS=="1-1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bMaxPower}==" 0mA"
ATTRS{urbnum}=="57"
ATTRS{idVendor}=="8087"
ATTRS{idProduct}=="0020"
ATTRS{bcdDevice}=="0000"
ATTRS{bDeviceClass}=="09"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="01"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="480"
ATTRS{busnum}=="1"
ATTRS{devnum}=="2"
ATTRS{version}==" 2.00"
ATTRS{maxchild}=="6"
ATTRS{quirks}=="0x0"
ATTRS{authorized}=="1"
looking at parent device '/devices/pci0000:00/0000:00:1a.0/usb1':
KERNELS=="usb1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bMaxPower}==" 0mA"
ATTRS{urbnum}=="26"
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}=="1"
ATTRS{devnum}=="1"
ATTRS{version}==" 2.00"
ATTRS{maxchild}=="3"
ATTRS{quirks}=="0x0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="Linux 2.6.32-31-generic ehci_hcd"
ATTRS{product}=="EHCI Host Controller"
ATTRS{serial}=="0000:00:1a.0"
ATTRS{authorized_default}=="1"
looking at parent device '/devices/pci0000:00/0000:00:1a.0':
KERNELS=="0000:00:1a.0"
SUBSYSTEMS=="pci"
DRIVERS=="ehci_hcd"
ATTRS{vendor}=="0x8086"
ATTRS{device}=="0x3b3c"
ATTRS{subsystem_vendor}=="0x10cf"
ATTRS{subsystem_device}=="0x1528"
ATTRS{class}=="0x0c0320"
ATTRS{irq}=="22"
ATTRS{local_cpus}=="ff"
ATTRS{local_cpulist}=="0-7"
ATTRS{modalias}=="pci:v00008086d00003B3Csv000010CFsd00001528bc0Csc03i20"
ATTRS{broken_parity_status}=="0"
ATTRS{msi_bus}==""
ATTRS{companion}==""
looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""
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