Hi,
I have a board with an IDT 92HD83C1X5 codec connected to an Intel HDA controller. When running a older "reference" Ubuntu 9.04 (provided by the vendor) the codec works fine. I've been diffing the sources provided of the 2.6.28 kernel against vanilla 2.6.28 and couldn't find any significant changes regarding HDA or the patch_sigmatel.c that has the support for this codec.
However, when I use kernel 2.6.34-rc6 on the same hardware, only one channel is working properly, all others remain muted. After some investigation I came up with the attached patch that makes all channels work again. I am aware that this is far from being acceptable code and that this is only a workaround. Still, I am interested in fixing this properly, but I don't really know where to start.
Also attached is an extract of dmesg with the actual output of the debugging messages added by the attached patch.
Cheers, Thierry