[Pcsclite-muscle] Multiple identical USB card readers

[it at mrtv.lt]

Thanks for the explanation,

2025-06-05 22:57, Ludovic Rousseau rašė:
> Le jeu. 5 juin 2025 à 16:41, it at mrtv.lt <it at mrtv.lt> a écrit :
>> Hello,
> Hello,
>
>> thank you for your reply. As far as I understand, the proposed solutions
>> allow to identify which reader is which after the system has booted.
>> However, reader identification is not my goal. The aim is to make sure
>> that the reader numbers do not swap, so that a reader inserted in the
>> appropriate slot is always identified, e.g. as “Reader 0”. These readers
>> do not have serial numbers. But they could be “bound” using other unique
>> attributes visible in the udevadm info (I noticed that the USB
>> controller number changes, but the USB port number stays the same, which
>> allows to build a udev rule). However, I don't know how to link these
>> attributes to the reader enumeration mechanism used by pcscd.
> The hotplug mechanism uses libudev (by default).
What does this hotplug mechanism actually do with USB readers? If we 
swap the USB readers and then run pcscd
--hotplug, we did not notice any effect. However, restarting pcscd
changes the enumeration of the readers.
  Is this hotplug mechanism applicable for USB readers? I found in the 
descriptions that it is for serial devices. How is it actually?
>
> The best I can propose is to provide a layer of indirection between a
> stable name using the USB bus and port (retrieved using
> SCARD_ATTR_CHANNEL_ID) and the PC/SC name.
> For example "Reader 1 5" would be the reader connected on USB bus 1 and port 5.
Perhaps that would solve my problem. Where and how to use this attribute?
Could you point out an example?
>
> Bye
>
> --
>   Dr. Ludovic Rousseau