Latin 2nd sg. passive

I had explained the 2nd pers. passives -(a/e/i)ris as a conjugated
form of the passive infinitive -()ri. After searching in the archive
it seems I made wrong assumption. Is there nothing to it?

I know that this doesn't fit with all conjugations, but cannot one
assume passive endinng -()ris in third conjugation as analogical to
the same found in 1st and 2nd conjugations?


Håvard