Re: another IDE cleanup: kill duplicated code

Andre Hedrick
2002-02-13T11:36:59Z

On Wed, 13 Feb 2002, Vojtech Pavlik wrote:

> > > None of this is relevant to IDE on Linux.
> >
> > Well not yet but here is a hint, all future hardware will be MMIO.
>
> That's nice. Actually, that's the case on many archs already.

Well I am totally aware of this issue and know it needs to be addressed.

> > Meaning all IO is performed under DMA over the ATA-Bridge.
>
> Ugh? This is not the meaning of your first sentence.

Surprise

> > Specifically PIO operations are transacted over VDMA to the Bridge and
> > executed as PIO by the Bridge.
>
> Care to explain in more detail? Hmm, I suppose not.
>
> I suppose you mean that the IDE controller will use BM DMA w/ SG for
> every transaction and the PIO/DMA/UDMA mode will only be different on
> the IDE BUS. That's very nice, and actually will make things simpler.
>
> I still don't see how any of the proposed patches kill the possibility
> to do this.
>
> > > Perhaps you mean PIO using SG-lists to put the data into the right
> > > places. But I still don't see a problem with this and the proposed patch.
> > >
> > > > Does a function struct for handling IO and MMIO help?
> > >
> > > Ugh? What is "function struct"?
> >
> > Since the future will be a mess, and it is possible to have IO/MMIO on the
> > same HOST it will be come more fun than you can imagine.
>
> The future (kernel point of view) will be how we make it to be. If we
> make a lot of messy code, the future will be a mess. This seems to be
> what you're doing. (Sorry.)

Oh I have the hardware and the newest stuff will have in a few days.
The future is Q3 2002 or sooner.

regards,

Andre Hedrick
Linux Disk Certification Project Linux ATA Development