lkml.org 
[lkml]   [1998]   [Dec]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: proper ioport space allocation
On Fri, 18 Dec 1998, Kurt Garloff wrote:

> On Thu, Dec 17, 1998 at 06:04:12PM -0600, Bob McElrath wrote:
>
> > Does anyone know if the PCI-ISA bridge blocks addresses with something other
> > than zero in the high word from reaching the ISA devices? (I assume PCI I/O
> > ports are 32-bits)
>
> PCI I/O is 32 bits (or even 64 on some architectures) and I think all
> addresses are forwarded to PCI bus, but the ones with the high word == 0
> also to ISA. Maybe there are optimizations to prevent the low addresses to
> be seen (and block?) the PCI bus ... I don't know.

PCI I/O address space is 16-bit. 32-bit I/O addresses may work if a
single PCI bus is present but they cannot cross PCI-PCI bridges.

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:46    [W:2.975 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site