Use a specific device ?

[Jean-Christian de Rivaz]

Le 05. 06. 15 15:51, poma a écrit :
> On 05.06.2015 15:37, Jean-Christian de Rivaz wrote:
>> 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
>>
>
> MM probing various hardware, not much of a news.
>

But still a problem. The lack of proper use of udev by ModemManager 
require creating a udev rule with ID_MM_IGNORE for all others serial 
devices. This is horribly wrong.

Jean-Christian