a) Is it possible to report more information alongside the plug events, such as ELD/EDID content? Or, is the idea that the kernel sends a plug event, and then user-space retrieves that information via some other API? I don't think there's an API to retrieve ELD information at present though right? Although certainly it'd make sense for that to be a completely separate patch.
A simple approach would be adding a control element containing byte-array of ELD/EDID.
Are there any examples of such controls? Or are we talking about a new kind of control? We could really use this ELD information in PulseAudio now that the passthrough mode is in git master; for now the codecs supported by the receiver are hard-coded, not a very reliable solution... -Pierre