Almost exactly a year ago (give or take an hour), we disabled AEN handling in mfii(4)
because it didn't work on SAS2208 controllers. I finally got around to looking into this
and found we were just missing one magical offset in one of the command structures. The
diff below add this and re-enables AEN processing.
I've tested on the following:
mfii0 at pci3 dev 0 function 0 "Symbios Logic MegaRAID SAS2208" rev 0x01: msi
mfii0: "PERC H710P Mini", firmware 21.0.2-0001, 1024MB cache
mfii0 at pci1 dev 0 function 0 "Symbios Logic MegaRAID SAS3108" rev 0x02: msi
mfii0: "PERC H730 Mini", firmware 25.4.0.0015, 1024MB cache
Could someone test on a SAS3.5 controller (megaraid 34xx or 35xx)? I don't have access to
one currently. All you need to do is boot the resulting kernel and check mfii0 isn't
generating interrupts constantly. Tests on other hardware would also be useful.