thank you for your answer. Finally I found, that backporting is not so necessary for me as I needed just three drivers - bt87x, via82xx and ice1724. Those drivers do not use newer functions I mentioned before, so the compilation has successfully ended.
But I noticed that even with the newset driver the alc655 line-in inputs do not work well. Before ( alsa 1.0.9 ) I had the right channel always connected to the Mic input. Now (Alsa 2008-08-22 ) in the right channel there is a copy of the left channel. Thus I have monophonic input instead of stereo.
I just downloaded the datasheet of ALC655 codec. I will read it hopefully tomorrow. But can you just advice me where to look to try to fix the problem ? It should be somewhere in snd_via82xx module ? Or somewhere else ? Inputs in snd_ice1724 (my second sound card) work properly. But I have never worked with kernel modules or kernel programming. I am just interested how to fix the problem I have.
Thank you in advance, Vaclav