MacBook Pro Mid 2012 b43 (4331) wifi disconnects
I just wanted to let you know that if you are having wifi problems with a Broadcom 4331 chip (MacBook Pro 9,2 / Mid 2012) you might want to use the following options for the b43 module:
(It takes a few weeks to test conclusively, so I haven't checked if individually either option is enough)
You can place them in a file like /etc/modprobe.d/b43.conf with:
options b43 nohwcrypt=1 qos=0
and then update your initramfs (update-initramfs -u).
You got them working if you see "b43-phy0 debug: QoS disabled" in your dmesg when you employ also the "verbose=3" option.