On Thu, 2015-07-30 at 14:14 +0200, Felix Fietkau wrote:

This ensures that mac80211 generated management frames and beacons 
are aligned before being passed to the driver

I'm not convinced this is appropriate. Drivers may or may not require
alignment, so I don't really see why we should in general enforce that?
Having less headroom requirement is better in general.

johannes