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

Bartlomiej Zolnierkiewicz
2009-11-26T14:55:26Z

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.

--
Bartlomiej Zolnierkiewicz