Bug#598518: linux-image-2.6-686: ata_piix module loaded before ahci module deactivate hotplug support (regression from lenny)

[Tejun Heo <htejun@gmail.com>]

Hello,

On 09/30/2010 12:27 AM, Ben Hutchings wrote:
> On Wed, 2010-09-29 at 18:50 +0200, thomas.debesse+debian@gmail.com
> wrote:
> [...]
>> ICH6 sata controller could be managed by both ata_piix and ahci module but only
>> ahci module handle hotplug.
>> At boot time, when ata_piix is loaded before ahci module, it takes control of
>> the ICH6 controller and the ahci module does'nt manage nothing. Because
>> ata_piix also manage ICH6 sata controller, hard drives are managed, but because
>> ata_piix module is used in place of ahci module, because ahci module is'nt
>> used, hotplug (and other ahci functionnalities indeed) does'nt works.
> [...]
>> The solution is to load ahci module before ata_piix module, then we can have
>> SATA drives managed by ahci module and IDE drives managed by ata_piix module.
> [...]
> 
> You can force ahci to be loaded first:
> 1. Add the line 'ahci' to /etc/initramfs-tools/modules.
> 2. Run 'update-initramfs -u' to regenerate the initramfs.
> 3. Reboot.
> 
> But it seems like it would be better if ahci was automatically
> preferred.

With modules.order in place, modprobe will always prefer ahci over
ata_piix (the preference follows the link order).  Maybe debian initrd
doesn't handle modules.order properly?

Thanks.

-- 
tejun