I’ve recently been doing some hacking on the Linux VIA IDE driver. The driver now supports multiple controllers on the same system (if such a situation could ever exist) and support has been added for the VT6410 and VT8251 chipsets.
All of this is included in Linux 2.6.15.
A side effect of this work is that we had to drop the /proc/ide/via file, a dynamic text file which provided some advanced information and stats about the VIA IDE hardware present on the system, and the attached disks. This kind of querying should be done in userspace anyway, so I have produced viaideinfo to do the same thing. viaideinfo has been tested by quite a few people and is now at version 0.3. It is in portage as sys-block/viaideinfo.
I have fired up the 2.6.15 patch and it does indeed add vt8251 PATA support, but still lacking the SATA portion of the controller. I found a patch at the website below, maybe you can make heads or tails of it and be able to make a patch for the ahci.c
http://www.uwsg.iu.edu/hypermail/linux/kernel/0512.1/0950.html
The message you linked to already contains a patch
yes, but I was unable to get it to work due to formatting and placement within the ahci.c source file. Im not saavy enough to fix the problems. I think the patch was based off of an older kernel source so its kinda break one to fix another :)
My website has the patch and full blown ahci.c for Kernel 2.6.15.1
Various people have tried it with success. It requires AHCI set in the bios. I use bios 210 for Asus MB, Others have used 5xx. It is not my patch, I just updated it for new kernel.