Re: [PATCH 16/86] pata_efar: MWDMA0 is unsupported

Alan Cox
2009-11-26T15:13:44Z

On Thu, 26 Nov 2009 15:53:58 +0100
Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> wrote:

> On Wednesday 25 November 2009 06:25:52 pm Alan Cox wrote:
> > On Wed, 25 Nov 2009 18:04:15 +0100
> > Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> wrote:
> >
> > > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
> > > Subject: [PATCH] pata_efar: MWDMA0 is unsupported
> > >
> > > MWDMA0 timings cannot be met with the PIIX based controller
> > > programming interface.
> >
> > The efar documentation makes no reference to not being capable of MWDMA0,
> > so where does this come from ? No MWDMA0 is an Intel erratum it appears.
>
> No MWDMA0 support is a common issue on all 'PIIX-like' controllers.
>
> In case of this chipset while the (preliminary) documentation claims MWDMA0
> support on the 'FEATURES' page the later 'programming guide' part describes
> only PIO0-4, SWDMA2, MWDMA1-2 and UDMA0-4 transfer modes as supported.

Cool - I only have the original docs.