Problem with 40Mhz on 2.5GHz with Intel 8260

[Volker Mische <volker.mische@xxxxxxxxx>]

Hi,

I'm having connectivity issues with an Intel 8260 on a 2.5GHz network
when using 40Mhz. I'm getting errors like

    Queue 2 stuck for 10000 ms.

I've upgrade my system to the firmware version 21 (21.373438.0) and
Kernel 4.8.0-rc6 in hope that it fixes the issue and to be able to debug
the problem.

I then found the page about platform noise [1]. I don't have any issue
for several hours now (normally I was hitting the issue every few
minutes) as I've set the cfg80211_disable_40mhz_24ghz parameter.

Now I wonder, is it worth debugging the issue with being on 40MHz or is
disabling the proper solution and I should bother.

[1]:
https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#about_platform_noise

Cheers,
  Volker