[alsa-devel] [PATCH] ALSA ymfpci - Don't create rear device, 4ch device and 4ch duplication switch when AC97 codec does not has SDAC bit

[PATCH] ALSA ymfpci - Don't create rear device, 4ch device and 4ch duplication switch when AC97 codec does not has SDAC bit

- check SDAC bit of AC97 primary codec when create "rear" device 3, "4ch" device 2 and "4ch Duplication" switch as the card need a four channels AC97 codec to support surround40.