Strange behaviour of ahci driver (intel 82801 Mobile SATA Controller)

Bug Description

Hi,

I have a MSI GS60E Ghost Pro laptop. It is quite complex:

2 SSD in raid 0 (intel Raid)
1 HDD standard SATA
2 Gpus (intel and nvidia)

I was trying to upgrade my trusty to utopic.

On trusty if I remember well there was no way to have a functionnal intel raid disks. I had to delete the raid an go to 2 separate disks to take advantage of the SSD (involved reinstalling secondary OS used for gaming).

Legacy boot:
On utopic, I can now use it but the name of the device is still strange (don't know if it is expected, but on other scsi harware I had I always had standard names /dev/sdx...):

/dev/mapper/isw_ihbcddegh_SSD, where SSD is the name given at raid creation of the volume.

Despite of this device I still have access to bare device /dev/sda, /dev/sdb, with the added bonus of being able to destroy the raid on it if we let the default /dev/sda for grub install of utopic desktop (destroyed at the end of install).

At install time we see /dev/mapper/isw_.... /dev/sda /dev/sdb and /dev/sdc, but it is readable on legacy installer even if not ideal.

UEFI boot:
If we boot on UEFI, it is more complex, as grub is not able to find the windows bootmanager for unknown reason (maybe not related).

Don't know if I need to put it somewhere else, but at the install selection of disks and partitions, it is also a bit confusing as it show two devices for the raid /dev/mapper/isw_.... each with the copy of the partitions (split the raid) plus bare devices, /dev/sda, /dev/sdb. I don't remember, if I saw partitions on the bare devices equaly.

I can make some undestructive tests for you (had hard time at making a working install on this machine). If really needed, I can switch to work on an other laptop, and go for destructive tests.

You can find some hardware infos about the config there, setup, etc:

http://paste.ubuntu.com/8478288/
---
ApportVersion: 2.14.7-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: kick 3322 F.... pulseaudio
 /dev/snd/controlC2: kick 3322 F.... pulseaudio
 /dev/snd/controlC1: kick 3322 F.... pulseaudio
CurrentDesktop: Unity
DistroRelease: Ubuntu 14.10
HibernationDevice: RESUME=UUID=46a8dc48-0696-4cc1-9ba5-6718ccae8802
InstallationDate: Installed on 2014-10-01 (0 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Alpha amd64 (20140923)
MachineType: Micro-Star International Co., Ltd. GS60 2PE
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.16.0-17-generic root=UUID=71fadb93-5ab3-4fab-98d7-e558816e33a0 ro quiet splash blacklist=nouveau
ProcVersionSignature: Ubuntu 3.16.0-17.23-generic 3.16.3
RelatedPackageVersions:
 linux-restricted-modules-3.16.0-17-generic N/A
 linux-backports-modules-3.16.0-17-generic N/A
 linux-firmware 1.134
Tags: utopic
Uname: Linux 3.16.0-17-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 08/16/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: E16H2IMS.10B
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: MS-16H2
dmi.board.vendor: Micro-Star International Co., Ltd.
dmi.board.version: REV:0.B
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrE16H2IMS.10B:bd08/16/2014:svnMicro-StarInternationalCo.,Ltd.:pnGS602PE:pvrREV1.0:rvnMicro-StarInternationalCo.,Ltd.:rnMS-16H2:rvrREV0.B:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: GS60 2PE
dmi.product.version: REV:1.0
dmi.sys.vendor: Micro-Star International Co., Ltd.