Use a specific device ?

[Jean-Christian de Rivaz]

Le 05. 06. 15 15:09, poma a écrit :
> On 05.06.2015 14:14, Jean-Christian de Rivaz wrote:
>> Le 05. 06. 15 13:18, Aleksander Morgado a écrit :
>>> On Tue, May 26, 2015 at 12:19 AM, Jean-Christian de Rivaz <jc at eclis.ch> wrote:
>>>> I have a system where the modem have multiple /dev/ttyACMx ports where x is
>>>> not constant because of the dynamic nature of others serial devices.
>>> It may be worth noting that a very similar issue with the one faced
>>> here is the one with network interface names, where interface names
>>> were created as kernel drivers probed the different interfaces, ending
>>> up with "eth0", "eth1" and so on. Then, there would be network
>>> interface configurations for each network interface based on the name,
>>> but no one really ensured that the name was the same upon reboots. The
>>> solution provided by systemd to ensure that the proper configuration
>>> is applied always to the proper interface is to make the device names
>>> "predictable", see:
>>> http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
>>>
>>> This solution avoids the need of any other udev rules to e.g. create
>>> network interface names containing the device MAC address or what not.
>>>
>>> I'm wondering whether the same could be applied not only to network
>>> interfaces, but also to ttyACMs, ttyUSBs and cdc-wdms, and end up
>>> having predictable tty names like e.g. /dev/ttyACMp0s20u4i0. Sure,
>>> those names are a nightmare to type, but they are predictable (e.g. in
>>> this case by including the physical location of the connector of the
>>> hardware).
>>>
>> This would be a wonderful solution. The only problem is when will this
>> feature be available in a stable Linux kernel widely used by all majors
>> distributions? Until this dream happens (probably not before severals
>> years I guess), an other option must be implemented.
>>
>> Jean-Christian
>
> Face your broadband modem, live your dreams?
>
> Kay, when this would happen - Predictable Broadband Modem Interface Names?
>

I must emphasis that this solution will still not solve the ModemManager 
problem of automatically probing any added serial devices, requiring all 
non-modem serial device to add the ID_MM_IGNORE hack in udev rules. This 
must change as soon as possible.

Jean-Christian