Re: Wi-Fi speeds degrade from 600Mps to 30Mps while using WPA2 security, but not on open network, shortly after ISP firmware upgrade.

[Johannes Berg <johannes@sipsolutions.net>]

On Thu, 2026-04-16 at 07:03 -0400, Benson Bear wrote:
> 
> (Sadly I think I might have an idea -- it's partly my fault.   The
> mac80211 module was disabling all HT and above because it
> felt it could not meet the BCS criteria laid down by the AP.
> Many people have thought these criteria were way too onerous.
> So I first had very low speeds because of that.  No HT even.
> I applied a patch to the module that ignored these requirements
> and got back to a high connection speed, and HE or VHT
> enabled, and got back a little of the lost speed.   Clearly very
> kludgy but seems a legitimate response to what the patch
> author called "aggressive basic MCS rates". But it may
> have opened up the room for misunderstandings.  I have my
> speed back in practice, but I wonder what the "correct" way
> of fixing this would be -- without the kludgy module patch).

I think what you're referring to here might be this?

https://lore.kernel.org/linux-wireless/99Mv9QEceyPrQhSP52MtAVmz0_kWJmzqotJjD9YW6LGLqk-AZloAueUyHCURilFkuqOh6Ecv8i2KKdSE1ujP3AnbU5QEouVisT1w_V3xdfc=@r26.me/

johannes