Re: [PATCH] libata: Add MMIO support to pata_sil680

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

> There are errata for config space and posting in some chipsets  and as you
> says its slow. The 400nS command writing bit applies too - they chipsets are
> not that smart in my experience.

Ok, I've start doing it, however, reset is the only case I've found.

Currently libata does the 400ns thingy in the inline ata_pause() which
unconditionally does ata_altstatus(); ndelay(400); (and thus does it on
PIO, MMIO, anything ...).

Do you want me to change that to use the MMIO flush hook as well ?

If we're going to do that, we probably need to be careful to have
everybody have a properly populated MMIO flush hook as there might be
current drivers (especially SATA) who rely on this. Jeff ?

Cheers,
Ben.