Comment 107 for bug 1040873

http://git.alsa-project.org/?p=alsa-lib.git;a=log;h=1af088e39b75a0a0897c7036487b143e983cd423

these two patches require 5.1 channel

and you need to hack the driver by putting speaker pin, headphone pin and subwoofer pin in multiout for 5.1

http://git.alsa-project.org/?p=alsa-lib.git;a=log;h=48f1b308cc66152eb6db66742dd0d08d888cda8

 these three seem try to remove the restriction