Re: [PATCH] pata_it8213: MWDMA0 is unsupported

Bartlomiej Zolnierkiewicz
2009-11-26T18:09:28Z

On Thursday 26 November 2009 06:23:18 pm Sergei Shtylyov wrote:
> Bartlomiej Zolnierkiewicz wrote:
>
> >>MWDMA0 timings cannot be met with the PIIX based controller
> >>programming interface.
>
> >>This change should be safe as this is how we have been doing
> >>things in IDE it8213 host driver for years.
>
> >>Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
> >>---
> >>Verified with the documentation (similar case as with pata_efar).
>
> > Uhhh, no...
>
> > Too many damn drivers.
>
> > Too much damn duplication.
>
> > Too much damn subtle differences here and there.
>
> > The hardware is probably fine for MWMDA0 when it comes to pata_{efar,it8213},
> > it just not documented properly in the data sheet.
>
> How so with pata_efar? The active/recovery bitfields are still 2-bit
> wide, no?

Yes but when TIMEx bit is disabled we are using XFER_PIO_SLOW timings.

All data sheets including original Intel ones are a complete crap when it
comes to explicitly documenting this behavior.

--
Bartlomiej Zolnierkiewicz