I'm sure that it's well known that FreeBSD iwm lacks 802.11n and 802.11ac support.
I believe OpenBSD supports 802.11n on iwm (I couldn't try OpenBSD as it doesn't boot on my laptop). A commit is here: https://github.com/openbsd/src/commit/d1ea7b2160ed2eb0df49e1e2db31cabcceb666cb
There is an abandoned GSoC project for FBSD 802.11n/ac: https://wiki.freebsd.org/SummerOfCode2017/Porting80211nAnd80211acToFreeBSDiwm
Would someone be willing to write a FreeBSD patch for at least 802.11n on iwm (if not ac)?
I doubt ac support will come soon, but it doesn't look too hard to port the OpenBSD changes for initial 802.11n support.
(In reply to Mark Johnston from comment #1)
Mark, are you working on this?
Any patches / progress?
(In reply to Andriy Gapon from comment #2)
Unfortunately I never got very far with this. At one point I had iwm using 11n rates, but the throughput was absymal. I didn't have much access to the AP I was testing against, so I bought another wifi card to use for that, thinking it was supported by FreeBSD, but it was not, and at that point I moved on to other things. I would still like to get back to it this summer, but I don't have any patches to share yet.