Load partially USB composite device

[Bjørn Mork]

loïc tourlonias <loic.tourlonias at gmail.com> writes:
> On Wed, Aug 9, 2017 at 9:25 AM, Bjørn Mork <bjorn at mork.no> wrote:
>
>> Sounds like your system has other issues, but whatever...
>
> I may not have been clear in my explanation. What seems wrong with my system?

"ethXX which interferes with a service". It should not.

>> The cdc_ether driver treats any ID entry with .driver_info = 0 as a
>> blacklist entry.  So you can dynamically blacklist devices by writing
>> the "VID PID" to /sys/bus/usb/drivers/cdc_ether/new_id before the device
>> is probed.
>>
> I have tried this and look at the source code of
> driver/usb/core/driver.c. But I think this is not what I required.
> What I understand is that the new_id file is used to dynamically add
> new USB id to the cdc_ether driver.

True.  But as I said: The cdc_ether driver use the device ID list for
blacklisting. This is an implementation detail specific to this driver.
It will use the .driver_info field as a pointer to usbnet specific data.
But if the field is 0, then the entry becomes a blacklist entry instead.

Dynamically added entries have all fields set to 0 by default, and will
also be tried before the built-in entries (since v3.15). So adding a
dynamic entry to the cdc_ether driver means adding a blacklist entry
(Unless you explicitly reference an existing entry for inheritance).

Try it.


Bjørn