Re: [PATCH RFC] ata: Intel IDE-R support

[Tejun Heo <tj@kernel.org>]

Hello,

On 08/18/2010 12:03 PM, Alan Cox wrote:
>> Sure, the thing is that your patch doesn't mean we don't have to keep
>> ata_piix device table up-to-date.  We would still need to be
>> maintaining that table whether ata_generic can detect IDE-R by itself
> 
> I'm not sure I follow

I was trying to say that IDE-R basically being the complement of Intel
IDE's not drive by ata_piix, we don't need to maintain a separate PCI
device ID table for IDE-R's.

>> or not.  The device ID table in ata_piix is given, and ata_generic
>> picking up the rest of intel IDE's wouldn't miss anything.  So, unless
>> IDE-R devices need some special treatment, I don't really see how the
>> detection code would be useful.
> 
> The trend is towards AHCI so the problem goes away for the other bits.

Yeah, it has helped a lot but ata_piix's are here to stay for the
foreseeable future and we'll be maintaining its device ID table.

> IDE-R is not ata_piix drivable, and lots of the ICH stuff really wants
> driving via ata_piix, so having the generic driver grab all intel stuff
> isn't as far as I can see going to be safe given a system may load the
> ata_generic module but not PIIX then meet a piix by hotplug.

That's the reason why we have module priorities.  The link priority
becomes module priority and modprobe will deterministically prefer
ata_piix over ata_generic if a controller is supported by both.

Thanks.

-- 
tejun