Re: [PATCH] ahci: AHCI and RAID mode SATA patch for Intel Cougar Point DeviceIDs

From: Robert Hancock
Date: Thu Jan 14 2010 - 19:16:06 EST

On Thu, Jan 14, 2010 at 2:11 PM, Henrique de Moraes Holschuh
<hmh@xxxxxxxxxx> wrote:
> On Wed, 13 Jan 2010, Robert Hancock wrote:
>> Hmm, it seems like it's a bit more complicated than that. For ICH6R
>> (0x2652), ata_piix attaches to it regardless of mode intentionally, it
>> has specific logic to disable AHCI on the controller since it can be
>> used in either mode. That seems a bit questionable. Having the same
>> device being handled by different enabled drivers and depending on
>> link or module load order to decide which one loads is fragile and
>> prone to errors. I'd be in favor of removing the ICH6R support from
>> ata_piix entirely and saying that you should be using ahci for that
>> device. Maybe when ahci was immature there was a benefit to allowing
>> ata_piix to run it, but I doubt that's true today.
> Maybe it is the silicon AHCI in ICH6R that is immature, and one is much
> better of using it in IDE mode?

That seems unlikely, since the Intel-provided Matrix Storage drivers
for that controller on Windows will be using AHCI mode..
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at