lkml.org 
[lkml]   [1999]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: New kernel/resource.c

On Sun, 25 Jul 1999, Linus Torvalds wrote:
>
> On Sun, 25 Jul 1999, Richard Henderson wrote:
> >
> > Hmm, actually we have more than 65536 generically on PCI. It's
> > just the x86 that limits to 64k. I actually ran into trouble
> > here the other day --
>
> Yeehaa..
>
> I wonder how many devices decode all 32 bits of an IO address. Maybe they
> all do, but it sure hasn't gotten any testing by anybody. Considering that

They aren't PCI compliant if they don't decode all 32 bits. Extract from
PCI v2.1 spec:

"The I/O Read command is used to read data from an agent mapped in I/O
Address Space. AD[31::00] provide a byte address. All 32 bits must be
decoded."

Ditto for I/O write. The area where PCI devices are likely to cheat on
address decoding is in the IO/mem base address regs, where some bits may
be hardwired to zeros.


-
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 13:53    [W:0.093 / U:0.460 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site