How can i get udev to make a link for me ?

Scuzz · 08-21-2009, 08:20 AM

I have lirc running and udev creates lirc0 in my /dev directory and i need it to be /dev/lirc .

I can create a link with ln -s lirc0 /dev/lirc and everything works fine but i want the link to be there everytime i bootup into slackware.

Iv tried adding ln -s lirc0 /dev/lirc to my /etc/udev/udev.conf but that just gives me an error on bootup.

Anyone have any ideas how i can achieve what im after ?

ilikejam · 08-21-2009, 08:39 AM

Hi.

Not tested, but should work...
Create a 10-local.rules file in /etc/udev/rules.d and in there put the line:
KERNEL=="lirc0", SYMLINK+="lirc"

Dave

rworkman · 08-21-2009, 08:43 AM

Quote:

Originally Posted by Scuzz

I have lirc running and udev creates lirc0 in my /dev directory and i need it to be /dev/lirc .

I can create a link with ln -s lirc0 /dev/lirc and everything works fine but i want the link to be there everytime i bootup into slackware.

Iv tried adding ln -s lirc0 /dev/lirc to my /etc/udev/udev.conf but that just gives me an error on bootup.

What made you think that would work?

Quote:

Anyone have any ideas how i can achieve what im after ?

Show the result of the following command:

Code:

udevadm info --attribute-walk --name /dev/lirc0

rworkman · 08-21-2009, 08:45 AM

Quote:

Originally Posted by ilikejam

Hi.

Not tested, but should work...
Create a 10-local.rules file in /etc/udev/rules.d and in there put the line:
KERNEL=="lirc0", SYMLINK+="lirc"

Yes, that should work, but the drawback is that multiple lirc* devices might cause the link to point at the wrong one. Ideally, the "udevadm info" results from what I posted in my previous reply will give us some unique information to key on.

Scuzz · 08-21-2009, 08:52 AM

Quote:

Originally Posted by rworkman

What made you think that would work?

Hahaha

That was my result of a google search.

udevadm info --attribute-walk --name /dev/lirc0 shows this info.

Code:

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/pci0000:00/0000:00:0b.0/usb2/2-2/2-2:1.0/lirc/lirc0':
    KERNEL=="lirc0"                                                                
    SUBSYSTEM=="lirc"                                                              
    DRIVER==""                                                                     

  looking at parent device '/devices/pci0000:00/0000:00:0b.0/usb2/2-2/2-2:1.0':
    KERNELS=="2-2:1.0"                                                         
    SUBSYSTEMS=="usb"                                                          
    DRIVERS=="lirc_mceusb2"                                                    
    ATTRS{bInterfaceNumber}=="00"                                              
    ATTRS{bAlternateSetting}==" 0"                                             
    ATTRS{bNumEndpoints}=="02"                                                 
    ATTRS{bInterfaceClass}=="ff"                                               
    ATTRS{bInterfaceSubClass}=="ff"                                            
    ATTRS{bInterfaceProtocol}=="ff"                                            
    ATTRS{modalias}=="usb:v0471p0815d0000dc00dsc00dp00icFFiscFFipFF"           
    ATTRS{supports_autosuspend}=="0"                                           

  looking at parent device '/devices/pci0000:00/0000:00:0b.0/usb2/2-2':
    KERNELS=="2-2"                                                     
    SUBSYSTEMS=="usb"                                                  
    DRIVERS=="usb"                                                     
    ATTRS{configuration}==""                                           
    ATTRS{bNumInterfaces}==" 1"                                        
    ATTRS{bConfigurationValue}=="1"                                    
    ATTRS{bmAttributes}=="a0"                                          
    ATTRS{bMaxPower}=="100mA"                                          
    ATTRS{urbnum}=="464"                                               
    ATTRS{idVendor}=="0471"                                            
    ATTRS{idProduct}=="0815"                                           
    ATTRS{bcdDevice}=="0000"                                           
    ATTRS{bDeviceClass}=="00"                                          
    ATTRS{bDeviceSubClass}=="00"                                       
    ATTRS{bDeviceProtocol}=="00"                                       
    ATTRS{bNumConfigurations}=="1"                                     
    ATTRS{bMaxPacketSize0}=="16"                                       
    ATTRS{speed}=="12"                                                 
    ATTRS{busnum}=="2"                                                 
    ATTRS{devnum}=="2"                                                 
    ATTRS{version}==" 1.10"                                            
    ATTRS{maxchild}=="0"                                               
    ATTRS{quirks}=="0x0"                                               
    ATTRS{authorized}=="1"
    ATTRS{manufacturer}=="Philips"
    ATTRS{product}=="eHome Infrared Transceiver"
    ATTRS{serial}=="PH00PrU2"

  looking at parent device '/devices/pci0000:00/0000:00:0b.0/usb2':
    KERNELS=="usb2"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{configuration}==""
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bmAttributes}=="e0"
    ATTRS{bMaxPower}=="  0mA"
    ATTRS{urbnum}=="86"
    ATTRS{idVendor}=="1d6b"
    ATTRS{idProduct}=="0001"
    ATTRS{bcdDevice}=="0206"
    ATTRS{bDeviceClass}=="09"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{speed}=="12"
    ATTRS{busnum}=="2"
    ATTRS{devnum}=="1"
    ATTRS{version}==" 1.10"
    ATTRS{maxchild}=="10"
    ATTRS{quirks}=="0x0"
    ATTRS{authorized}=="1"
    ATTRS{manufacturer}=="Linux 2.6.29.6-smp ohci_hcd"
    ATTRS{product}=="OHCI Host Controller"
    ATTRS{serial}=="0000:00:0b.0"
    ATTRS{authorized_default}=="1"

  looking at parent device '/devices/pci0000:00/0000:00:0b.0':
    KERNELS=="0000:00:0b.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="ohci_hcd"
    ATTRS{vendor}=="0x10de"
    ATTRS{device}=="0x036c"
    ATTRS{subsystem_vendor}=="0x1043"
    ATTRS{subsystem_device}=="0xcb84"
    ATTRS{class}=="0x0c0310"
    ATTRS{irq}=="23"
    ATTRS{local_cpus}=="ffffffff"
    ATTRS{local_cpulist}=="0-31"
    ATTRS{modalias}=="pci:v000010DEd0000036Csv00001043sd0000CB84bc0Csc03i10"
    ATTRS{enable}=="1"
    ATTRS{broken_parity_status}=="0"
    ATTRS{msi_bus}==""

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

Scuzz · 08-21-2009, 10:00 AM

Quote:

Originally Posted by ilikejam

Hi.

Not tested, but should work...
Create a 10-local.rules file in /etc/udev/rules.d and in there put the line:
KERNEL=="lirc0", SYMLINK+="lirc"

Dave

Thank you sir , it works.

rworkman · 08-21-2009, 01:06 PM

The following should key on that specific lirc device. Honestly though, if you only have one, then the line you're using now is fine.

Code:

SUBSYSTEMS=="usb", \
  ATTRS{manufacturer}=="Philips", \
  ATTRS{product}=="eHome Infrared Transceiver", \
  ATTRS{serial}=="PH00PrU2", \
  SYMLINK+="lirc"

Scuzz · 08-21-2009, 03:12 PM

Quote:

Originally Posted by rworkman

The following should key on that specific lirc device,

Code:

SUBSYSTEMS=="usb", \
  ATTRS{manufacturer}=="Philips", \
  ATTRS{product}=="eHome Infrared Transceiver", \
  ATTRS{serial}=="PH00PrU2", \
  SYMLINK+="lirc"

Just for the sake of learning something new at this point, Would i insert your code snippet into /etc/udev/rules.d/10-local.rules or some other location?

rworkman · 08-21-2009, 11:57 PM

Yeah, 10-local.rules is fine. Comment out the first part you already added though (or delete it).