Comment 31 for bug 731706

Until very recently, I had never needed to use the microphone on my Dell Studio 1558. Then I discovered it did not work under 11.10 Onieric. I confirmed the bypass of redefining the active microphone with alsamixer worked, indicating that pulseaudio was choosing the "wrong" microphone to make active.

In case anyone is interested, the microphone is working well under the 12.04 Precise Pangolin Beta. I presume the appropriate quirk was integrated into the 3.2.0-17 kernel.

(n.b. lspci shows Intel Corp 5 series/3400 with a device id [8086:3b56] )