OK, I was looking at the files in kernel 4.0 rc6, which do not have a core
structure.
I guess this must be a recent change in alsa. Sorry to bother you.
William G. Unruh | Canadian Institute for| Tel: +1(604)822-3273
Physics&Astronomy | Advanced Research | Fax: +1(604)822-5324
There is a patch in ALSA for the Dell XPS 13 HDA sound system.
http://mailman.alsa-project.org/pipermail/alsa-devel/2015-March/089789.html
This patch appears to have a bug. It refers to codec->core.version_id
where codec is a hda_codec structure. Unfortunately that structure has no core
member.