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

[Gleb Natapov <gleb@redhat.com>]

On Tue, May 15, 2012 at 04:22:26PM +0100, Alan Cox wrote:
> On Tue, 15 May 2012 17:53:16 +0300
> Gleb Natapov <gleb@redhat.com> 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.
> 
Hmm, will work if standard I/O addresses are used for master/slave, but
I do not see this information be exposed via /sys by EDD. So how can I
do it from OS installer with current kernel or kernel with reverted
patch?

> 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

--
			Gleb.