> > i'm 99% sure it's coincidence, the pcie version or connector shape
> > shouldn't matter.
it both does and doesn't
intel changed the firmware significantly in the 7000 series, which
coincides with intel's mpcie->m2 switch in wifi cards
there are both 6000 series m2 cards as you mentioned and 7000 series
mpcie cards (7260-7265 have mpcie versions to my knowledge)
so this problem is about 7000+ series of cards
(3000 series are 1x1 versions of 7000)

because of this a different code path exists for initialization,
there's probably
some bug in it. i checked the latest patch i prepared a long time ago
for 7260 support and i realized there was a change i made that i forgot
about (maybe i didn't send that patch at all, i don't remember...)
the calibration commands in the main firmware initialization doesn't include
type+length in the command itself and simply sends the calibration block
it may have caused the firmware to ignore calibration commands, which
would result in botched calibration+slow speeds.
(although if this was the case i'd expect the firmware returning a error
to the driver, so i'm not sure on this)
i prepared a patch to include this change

i also cleaned up fw capability checking and added pci ids for 3165-3168
as those should work out of the box with the current code

i can't test this patch, so i will attach it for those who want to test

it can get pushed if it works