Re: Assorted bugs in the PIIX drivers

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

On Llu, 2006-05-15 at 19:12 +0400, Sergei Shtylyov wrote:
>     For PIO2+ actually, according to Intel's PRM (29860004.pdf), and it's said
> to have no effect in the lower modes. This is actually not very correct since
> when one issues Set Transfer Mode ATA command with the value (8 + PIOn), this
> means select PIO _flow control_ mode n, so -IORDY is assumed to be in use.

PIO2 depends on the drive (there is a drive parameter telling you the
highest timing clock you can do with/without IORDY

> > I'm also not clear if the "no MWDMA0" list has been updated correctly
> > for the newer chipsets.
> 
>     What is/was the point for keeping MW DMA 0 support anyway? On PIIX, it's
> greatly slowed down (600 vs 480 ns cycle) and was never "offically" supported
> by Intel.

Some old old drives only do MWDMA0. The Intel docs I have here don't
describe it in any way as "unsupported", merely broken on some ICH
variants.

Alan