In this version of alsa driver Mic As Center/LFE has a wrong type and value control.47 { comment.access 'read write' comment.type INTEGER comment.range '0 - 0' iface MIXER name 'Mic As Center/LFE' value 0 } instead of .type Boolean I don't check 2.6.4 for that but in 2.6.2 and earlier, I had used 5.1 output. In this version i can use only Mic and can't switch to output additional channels.
Cool, about a month without any question, suggestion or something that says that we are still not dead. I want my Center/LFE channel back. Could anyone answer how i can patch ac97_patch.c at line 1085 to get nor amixer cget numid=47 numid=47,iface=MIXER,name='Mic As Center/LFE' ; type=INTEGER,access=rw---,values=1,min=0,max=0,step=0 : values=0 that completly wrong but something like amixer cget numid=45 numid=45,iface=MIXER,name='Line-In As Surround' ; type=BOOLEAN,access=rw---,values=1 : values=off
Created attachment 31599 [details, diff] Patch that makes Mic -Center/LFE workable again
This is a upstream bug, please file it at bugzilla.kernel.org.