Using iwpriv to set cwmin or cwmax does not take effect. No matter what value I set it to other than 4

iwpriv ath0 get_cwmin returns 4.

So even if I run iwpriv ath0 cwmin 0 1 1

iwpriv ath0 get_cwmin still returns 4.

I have already tried to hard code these parameters in the source files but then the machine kernel panics with the module.