Hi !
i just read up again on this: http://www.mail-archive.com/vdr@linuxtv.org/msg13224.html
Actually i think this would be also a good starting for
a) save some energy - if DVB devices are not opened all the time, the driver has the chance to put it into standby saving some heat, energy and lifetime of the cards
b) have a beginning of dvb device hotplug - if dvb devices are discovered on demand, its a good chance at a later stage to also add and remove cards on the fly. There is sure some notification required from udev to vdr so it can keep internal reference of the how many devices are there.
Not that i could help in doing this - being aware it might take a while until its finished - but i still thought to share my thoughts, that this addition is not only usefull for shared frontends, but also for general usage.
Hope the work on this is continued and possibly accepted by Klaus after some review and as work in progress.
Kind Regards
Steffen