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Yes, IP handles data reception and data transfer outside of iio context. > >> >> But that being said, I'm leaning towards thinking that perhaps a >> minimalistic backend should always be registered after all. That would >> keep the idea of the backend always existing intact. >> But since the backend can be missing a lot of the features defined for >> the current ADI backend, capability handling would need to be added to >> the backend framework to make it functional. >> >> Looking into how this could be achieved with reasonable impact, I have >> tried to identify capabilities that we could add for starters, and then >> have the frontend behave differently depending on what features are present. >> >> Something like this (added to backend_info), >> .caps = IIO_BACKEND_CAP_TEST_PATTERNS |  --> backend patterns are avail. >> IIO_BACKEND_CAP_BUFFERING |  --> backend has buffering cap. >> IIO_BACKEND_CAP_CALIBRATION, --> backend supports calibration >> > > Looks reasonable but I'm still a bit afraid to open this can of worms. But as Jonathan > pointed out multiple times on the backend code, this is mostly inkernel interfaces so > it is easier to deal with bad choices :). I understand this concern, but would anticipate that there are only a limited number of capabilties that need to be handled, so it should stay fairly managable. > > > We would still need to "combine" these capabilities feature with a dummy backend that > would dummy implement the more common/expected like (chan)enable/disable and so on. I think the dummy backend is probably not gonna be needed as the current axi backend can advertise the available set of capabilities. The frontends are then free to make use of the capability bits as needed. In my use case, I need to implement a limited backend that does not claim any capabilities but only provides a minimum set of functionality. Thanks, Tomas > > We can then decide on a usecase by usecase basis on what should be a capability or what > should be dummy implemented. > > Bottom line, I'm leaning on "I'm ok with the above" since I expect usecases like this to > be fairly rare (famous last words :)). And It would be nice to have more feedback > on this one. > > - Nuno Sá >