Re: libata PATA support - work items?

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

On Mer, 2005-01-05 at 02:42, Jeff Garzik wrote:
> > - IORDY timers (not handled well in drivers/ide but needed)
> I think I know what this is.

The SII has support for this in the h/w btw (see the docs). Otherwise
IDE as a protocol can get stuck if the drive enters rotating doorstop
mode at the wrong moment.

> > - Funky Maxtor "LBA48.. maybe" oddments
> details?

There are a couple of "yes we do LBA48" "no we don't do this command in
LBA48" cases with maxtors (Cache flush is one, the stroke stuff triggers
another)

> > - Missing slave detection
> 
> Not missing, master/slave has been working for ages.  Needed for 
> combined mode, where a SATA device can appear as a slave.

No no - some devices have a master and a slave on them when you detect
but only one disk attached because they forgot to bother decoding it in
the adapter (eg some pcmcia with microdrives). This causes bad shit
especially with hal style automounting.

> > - Bandwidth arbiter (not in drivers/ide but needed)
> interesting

Its effectively serialize I think that is needed but with >1 at a time.

> > - Non PCI shared IRQ mess 8(
> details?

ISA IRQ lines - two controllers, one IRQ but edge triggered and not
sharable directly. The core old IDE code actually supports all of this
and people have run stuff like 6 ISA IDE controllers in a PC.[1]

Alan
[1] Seek medical advice before trying this at home