HTML and other documentation in not generated from DocBook files found in Documentation/sound/alsa/DocBook/ since there is no Makefile for them.
The most logical solution is to move the 2 files in Documentation/DocBook/ and add them to the relative Makefile.
Done. Patch is at http://oss.oracle.com/~rdunlap/patches/docbook-move-alsa-docs.patch
The patch can't be applied to the latest sound git tree, unfortunately.
Could you rebase the patch against it?
Please try this new patch:
Thanks, applied now. Should appear in the next linux-next tree.