Strange Behaviour with udev
Hello,
I have problems with the assignment of symbolic links with udev. I am
using two usb-serial converter. I need them always on the same device.
So I am using udev rules (z61-sht-sensor.rules):
ATTRS{serial}=="A2001nj4", SUBSYSTEMS=="usb", ATTRS{idVendor}=="0403",
ATTRS{idProduct}=="6001", SYMLINK+="temp1"
ATTRS{serial}=="A2001muZ", SUBSYSTEMS=="usb", ATTRS{idVendor}=="0403",
ATTRS{idProduct}=="6001", SYMLINK+="temp2"
When I switch on the Device everything is OK. The link is created:
lrwxrwxrwx 1 root root 7 Mar 29 18:52 /dev/temp1 -> ttyUSB0
crw-rw---- 1 root dialout 188, 0 Mar 29 19:05 /dev/ttyUSB0
When I Unplug an then plug in the Device again it looks like:
lrwxrwxrwx 1 root root 15 Mar 29 19:05 /dev/temp1 -> bus/usb/001/005
crw-rw-r-- 1 root root 189, 4 Mar 29 19:05 /dev/bus/usb/001/005
Then I called udevtrigger. This results in the following:
lrwxrwxrwx 1 root root 14 Mar 29 21:31 /dev/temp1 -> usbdev1.5_ep81
crw-rw---- 1 root root 442, 4 Mar 29 19:05 /dev/usbdev1.5_ep81
My System is a nslu2 with debianslug.
# uname -a
Linux LXXX 2.6.18-6-ixp4xx #1 Sat Dec 27 23:27:54 UTC 2008 armv5tel
GNU/Linux
udevtest has the following output
# udevtest /sys/class/tty/ttyUSB0
parse_file: reading '/etc/udev/rules.d/020_permissions.rules' as rules file
parse_file: reading '/etc/udev/rules.d/udev.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z20_persistent-input.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z20_persistent.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z25_persistent-net.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z45_persistent-net-generator.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z50_run.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z55_hotplug.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z60_nslu2-rtc.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z61-sht-sensor.rules' as rules file
parse_file: reading '/etc/udev/rules.d/z75_cd-aliases-generator.rules' as rules file
This program is for debugging only, it does not create any node,
or run any program specified by a RUN key. It may show incorrect results,
if rules match against subsystem specfic kernel event variables.
main: looking at device '/class/tty/ttyUSB0' from subsystem 'tty'
udev_rules_get_name: add symlink 'temp1'
udev_rules_get_name: no node name set, will use kernel name 'ttyUSB0'
udev_device_event: device '/class/tty/ttyUSB0' already in database, validate currently present symlinks
udev_node_add: creating device node '/dev/ttyUSB0', major = '188', minor = '0', mode = '0660', uid = '0', gid = '20'
udev_node_add: creating symlink '/dev/temp1' to 'ttyUSB0'
main: run: 'socket:/org/kernel/udev/monitor'
The output of udevinfo is:
# udevinfo -a -p /sys/class/tty/ttyUSB0
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 '/class/tty/ttyUSB0':
KERNEL=="ttyUSB0"
SUBSYSTEM=="tty"
DRIVER==""
ATTR{dev}=="188:0"
looking at parent device
'/devices/pci0000:00/0000:00:01.0/usb1/1-1/1-1.1/1-1.1:1.0/ttyUSB0':
KERNELS=="ttyUSB0"
SUBSYSTEMS=="usb-serial"
DRIVERS=="ftdi_sio"
looking at parent device
'/devices/pci0000:00/0000:00:01.0/usb1/1-1/1-1.1/1-1.1:1.0':
KERNELS=="1-1.1:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="ftdi_sio"
ATTRS{interface}=="FT232R USB UART"
ATTRS{modalias}=="usb:v0403p6001d0600dc00dsc00dp00icFFiscFFipFF"
ATTRS{bInterfaceProtocol}=="ff"
ATTRS{bInterfaceSubClass}=="ff"
ATTRS{bInterfaceClass}=="ff"
ATTRS{bNumEndpoints}=="02"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bInterfaceNumber}=="00"
looking at parent device
'/devices/pci0000:00/0000:00:01.0/usb1/1-1/1-1.1':
KERNELS=="1-1.1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{latency_timer}=="16"
ATTRS{configuration}==""
ATTRS{serial}=="A2001nj4"
ATTRS{product}=="FT232R USB UART"
ATTRS{manufacturer}=="FTDI"
ATTRS{maxchild}=="0"
ATTRS{version}==" 2.00"
ATTRS{devnum}=="5"
ATTRS{speed}=="12"
ATTRS{bMaxPacketSize0}=="8"
ATTRS{bNumConfigurations}=="1"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceClass}=="00"
ATTRS{bcdDevice}=="0600"
ATTRS{idProduct}=="6001"
ATTRS{idVendor}=="0403"
ATTRS{bMaxPower}==" 90mA"
ATTRS{bmAttributes}=="a0"
ATTRS{bConfigurationValue}=="1"
ATTRS{bNumInterfaces}==" 1"
looking at parent device '/devices/pci0000:00/0000:00:01.0/usb1/1-1':
KERNELS=="1-1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{product}=="Generic USB Hub"
ATTRS{manufacturer}=="ALCOR"
ATTRS{maxchild}=="4"
ATTRS{version}==" 1.10"
ATTRS{devnum}=="3"
ATTRS{speed}=="12"
ATTRS{bMaxPacketSize0}=="8"
ATTRS{bNumConfigurations}=="1"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceClass}=="09"
ATTRS{bcdDevice}=="0312"
ATTRS{idProduct}=="9254"
ATTRS{idVendor}=="058f"
ATTRS{bMaxPower}=="100mA"
ATTRS{bmAttributes}=="e0"
ATTRS{bConfigurationValue}=="1"
ATTRS{bNumInterfaces}==" 1"
looking at parent device '/devices/pci0000:00/0000:00:01.0/usb1':
KERNELS=="usb1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{serial}=="0000:00:01.0"
ATTRS{product}=="OHCI Host Controller"
ATTRS{manufacturer}=="Linux 2.6.18-6-ixp4xx ohci_hcd"
ATTRS{maxchild}=="3"
ATTRS{version}==" 1.10"
ATTRS{devnum}=="1"
ATTRS{speed}=="12"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{bNumConfigurations}=="1"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceClass}=="09"
ATTRS{bcdDevice}=="0206"
ATTRS{idProduct}=="0000"
ATTRS{idVendor}=="0000"
ATTRS{bMaxPower}==" 0mA"
ATTRS{bmAttributes}=="e0"
ATTRS{bConfigurationValue}=="1"
ATTRS{bNumInterfaces}==" 1"
looking at parent device '/devices/pci0000:00/0000:00:01.0':
KERNELS=="0000:00:01.0"
SUBSYSTEMS=="pci"
DRIVERS=="ohci_hcd"
ATTRS{broken_parity_status}=="0"
ATTRS{enable}=="1"
ATTRS{modalias}=="pci:v00001033d00000035sv00001033sd00000035bc0Csc03i10"
ATTRS{local_cpus}=="1"
ATTRS{irq}=="28"
ATTRS{class}=="0x0c0310"
ATTRS{subsystem_device}=="0x0035"
ATTRS{subsystem_vendor}=="0x1033"
ATTRS{device}=="0x0035"
ATTRS{vendor}=="0x1033"
looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""
Is there anything wrong in the rule?
Why udev always crates a different symbolic link?
Thanks for help
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