[asterisk-dev] Sysfs udev /dev/dahdi/span-names/ population

Oron Peled oron.peled at xorcom.com
Sat Jul 24 16:10:57 CDT 2010


On Saturday, 24 בJuly 2010 22:49:05 Kevin P. Fleming wrote:
> The driver should expose the various pieces of information it
> has available, and the admin can create a suitable udev rule (probably
> by copying an example that would exist in the docs) based on whether
> they prefer to use the connector string or the label... 

It is exactly what the driver/udev rules do in this branch. It is
handled as follows:
 * The driver exposes "location", "hardware_id" and "hardware_port"
    as span attributes in sysfs

 * A script that runs from udev, uses this information to create the
   namespaces under /dev/dahdi

We didn't have to invent the wheel for this, a quick look under /dev/disk
would clearly show on whose shoulders we stood ;-)

Few other quick notes:
 * Current DAHDI PCI cards don't have any on-board ID so  identifying
   hardware by its location makes this feature usefull also for non-Xorcom
   devices until their vendors choose to implement hardware-id's (hint ;-)

 * The optional "aliases" which are implemented by a separate script
   allow the administrator to give "nicer" names to their devices:

   - It improve readbility of device paths in the dialplan
     (e.g: DAHDI/main-office!5 )

   - It can solve problems if the hardware ID or the location contains
     characters which are invalid in the dialplan, chan_dahdi.conf or
     system.conf

   - It allows an administrator to replace a faulty device with an identical
     one, regardless of its hardware_id/location by editing a single mapping
     file.

Bye,

-- 
Oron Peled                                 Voice: +972-4-8228492
oron at actcom.co.il                  http://users.actcom.co.il/~oron
Linux lasts longer!
                        -- "Kim J. Brand" <kim at kimbrand.com>



More information about the asterisk-dev mailing list