[PATCH v3][for 4.14] xhci: allow TRACE to work with EVENT ring dequeue

From: Adam Wallis

Sent: 25 September 2017 13:26
inc_deq() currently bails earlier for EVENT rings than the common return
point of the function, due to the fact that EVENT rings do not have
link TRBs. The unfortunate side effect of this is that the very useful
trace_xhci_inc_deq() function is not called/usable for EVENT ring
debug.

Is it actually worth using different functions for the different
ring types?

From what I remember there are conditionals in a lot of the functions

but they are fixed for most of the call sites.

	David