Re: libata in 2.4.24?

[Mike Fedyk <mfedyk@matchmail.com>]

On Tue, Dec 02, 2003 at 01:04:58PM -0500, Jeff Garzik wrote:
> On Tue, Dec 02, 2003 at 09:40:48AM -0800, Mike Fedyk wrote:
> > There are PATA drives that do TCQ too, but you have to look for that feature
> > specifically.  IDE TCQ is in 2.6, but is still experemental.  I think Jens
> > Axboe was the one working on it IIRC.  He would have more details.
> 
> Let us distinguish three types of TCQ:
> 1) PATA drive-side TCQ (now called "legacy TCQ")
> 2) Controller-side TCQ
> 3) SATA drive/controller-side TCQ ("first party DMA")
> 
> libata will never support #1, which is what 2.6 supports in experimental
> option.

An experemental option with the ide layer, not libata, right?

> 
> libata will support #2 very soon, and will support #3 when hardware is
> available.
> 

If you have Controller-side TCQ, then will it work with any IDE PATA/SATA
drive?

> > > Do the new SATA drives and controllers provide a solution to this?
> > 
> > It's not SATA specific, and I'm not sure if any ide controller can support
> > TCQ or if only a specific list are compatible.
> 
> The TCQ you are thinking of has been deprecated by the people who make
> IDE drives ;-)

Ahh, it's good to know that our TCQ support isn't lagging.  We're even
supporting TCQ standards that were only in place for 1 or 2 years. :)