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0e1f616
(Get the code!)
Jani and I had a conversation about this not-so-very-long ago. Unfortunately, the spec is rather vague on the details of AUX_DEFERs. There's a little bit more information in there for I2C-over-AUX behavior, but nothing directly about native AUX_DEFERs as far as retry timeouts go. Essentially the spec just says "the source device can try again later" and leaves it at that. There's also an instance in the spec that says "assumes the Source repeats request immediately following a DP Sink AUX Defer response". Nothing like consistency...
That said, I would think that up to 300us would be a safe value for a retry timeout. That should be fine for isolated DEFERs or even a short series of them. However, lots of defers with a timeout value like this can stretch AUX operations out beyond specified specified time limits (10ms for link training for instance), so that's something to keep in mind.
-T