[Lucid] SRU: [PATCH] UBUNTU: Make ahci ignore the controller for MBP7, 1 and fall back to ata_generic. Patch based on Tejun Heo's submitted upstream.

[Stefan Bader]

As of today, this change is upstream but as two separate patches. I took the
liberty to do provide them as backported in your name.
Both have the necessary tags to make them go upstream stable and should come in
one of the next stable releases. But due to the fact that an installation is not
possible without that changes on the affected hw, I think it is sensible to take
them pre-stable. Changes are limited to specific device, so regression potential
is low.

-Stefan

For the split up version of patches.
Acked-by: Stefan Bader <stefan.bader at canonical.com>

On 07/02/2010 01:37 AM, Dave Walker wrote:
> The Linux kernel doesn't currently support the latest generation of the
> Macbook Pro (7,1), and also seems to have issues with the MacBook Mini.
>  The issue presents itself as SATA support being unavailable once the
> initrd tries to reset the SATA device.
> 
> There is a high priority open bug[0] regarding this, and at time of
> writing 106 Launchpad users have shared that the bug affects them (aka
> "me too")
> 
> The patch attached is heavily based on the work of Tejun Heo who has
> submitted it upstream[1] (and submitted to stable).  The changes to this
> patch include some slight refactoring to which make it compatiable with
> the 2.6.32 code, and a manual refresh to apply cleanly to the lucid git
> tree.
> 
> Based on looking what the patch achieves, i might suggest that the
> regression potential is low as it essentially blacklists if the
> following conditions are met:
> - The vendor of the SATA device is nvidia
> - The device is MCP89
> - The hardware is Apple
> - Particular subsystem id
> 
> If the blacklist is achieved, then ahci ignores the controller and
> allows fall back to ata_generic.
> 
> Whilst it hasn't yet been applied to Linus' git tree (so can't send a
> stable pull request), I would personally consider it paramount that this
> patch is applied soon to the Lucid kernel with the hope of landing on
> the 10.04.1 cd image.
> 
> As it stands, Ubuntu users with this hardware are unable to install from
> the 10.04 cd image, and are currently dependent on using an community
> built unofficial iso to be able to install Ubuntu.
> 
> Based on the high "me too" on Launchpad, I feel that many users are
> highly dependent on this landing in an official cd spin, and am
> therefore hoping that this patch is included and an SRU is created in
> time for the 10.04.1 release.
> 
> The original author of this patch described it as:
> "For yet unknown reason, MCP89 on MBP 7,1 doesn't work w/ ahci under
> linux but the controller doesn't require explicit mode setting and
> works fine with ata_generic.  Make ahci ignore the controller on MBP
> 7,1 and let ata_generic take it for now." -- Tejun Heo
> 
> Thanks
> 
> [0] http://bugs.launchpad.net/bugs/576601
> [1] http://article.gmane.org/gmane.linux.ide/46514
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-ahci-ata_generic-let-ata_generic-handle-new-MBP-w-MC.patch
Type: text/x-diff
Size: 3532 bytes
Desc: not available
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20100702/80881619/attachment.patch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0002-ata_generic-implement-ATA_GEN_-flags-and-force-enabl.patch
Type: text/x-diff
Size: 4523 bytes
Desc: not available
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20100702/80881619/attachment-0001.patch>