Re: [PATCH] EDD: Check for correct EDD 3.0 length

[Alan Cox]

On Tue, 15 May 2012 17:53:16 +0300
Gleb Natapov <gleb@xxxxxxxxxx> wrote:

> On Tue, May 15, 2012 at 03:52:06PM +0100, Alan Cox wrote:
> > > It is easy to be confused since there are two EDD 3 specs. First is from
> > > Phoenix BIOS (linked at the first mail of the thread) and it does not have
> > > enough info even for ATA. You can't tell primary ATA controller from secondary.
> > 
> > Yes you can - it's defined by the PCI specification for compatibility
> How? ATA device path has only Master/Slave. Interface path has only
> bus/slot/function. So given all that in int13_80 how do I know if this
> is primary or secondary controller?

For compatibility mode by the I/O port address.

For native mode most controllers pretend to be two devfns for exactly
this reason, and report one on each. Some non-MMIO devices don't and you
can tell them apart by looking at the addresses given in DPTE as well.

Simples.. 

Alan
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