ID_MM_DEVICE_MANUAL_SCAN_ONLY not applied properly?

Bjørn Mork bjorn at
Fri May 18 16:20:50 UTC 2018

Bjørn Mork <bjorn at> writes:
> Aleksander Morgado <aleksander at> writes:
>>>> The ID_MM_DEVICE_MANUAL_SCAN_ONLY is applied on the usb_device matched
>>>> by vid:pid from the list of rules we have.
>>>> This first run is after booting the machine: I don't see the tag applied.
>>> Maybe you forgot to update your initramfs after adding the new rule?
>> Hum... why would that be needed? udev rules are applied on boot as
>> soon as the USB devices gets exposed by the system. Or am I missing
>> something?
> This tends to happen before the real root system is mounted.  And there
> is no later rediscovery of already discovered USB devices.  At least
> that's how I thought this worked.  Could be wrong, as usual...
> Looking at my initramfs I guess I must be.  I note that *some* udev
> rules are copied there.  But most of them are not, and in particular the
> default MM rules.  Weird.  Have to look further at this.

The responsible for that is this hook, which has a short hardcoded list
of rules to copy:

I wonder why?  I would have thought that you either needed all or none?


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