Re: libata and PATA devices

[Jeff Garzik <jgarzik@pobox.com>]

Erik Slagter wrote:
> On Sat, 2005-08-13 at 11:56 -0400, Jeff Garzik wrote:
> 
>>>Nope. The harddisk is not SATA, it's PATA. See the links I posted
>>>earlier. That's the whole point.
>>
>>The controller thinks its a SATA device, so there is probably a bridge 
>>installed.
> 
> 
> I suppose it's something like that.
> 
> It's all very confusing.
> 
> E.g. that would mean I must treat my PATA harddisk as if it's a SATA
> harddisk, but on the other hand, it's not really a SATA disk, so I
> cannot use SATA features.
> 
> Maybe an idea to spend a few words on the matter, including the way
> you're supposed to configure the kernel for this setup.

Sounds like you've hit on the configuration, in the previous email. 
Yes, it does mean no DMA for the DVD drive.


> BTW afaik you won't be able be able to control DMA on the dvd drive with
> this setup, so I'll stick to my patched kernel for the moment (= both
> disk&cdrom are assigned to ide).

That's normal for combined mode.  Until libata can do ATAPI (soon!), the 
lack of DMA is a necessary evil, since two drivers are trying to claim 
two halves of the same hardware.

	Jeff