lkml.org 
[lkml]   [2001]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: mpparse.c question

On Fri, 2 Feb 2001, Maciej W. Rozycki wrote:

> > Can that happen, is that important?
> >
> > Silly question: Why can't we ignore all but the first pin? If we don't
> > enable the additional pins, we don't have to disable them during
> > disable_irq().
>
> Possibly yes -- I haven't seen such a system.

it does exist, and the feature fixed a real bug. I dont remember which
system exactly :-|

> > Btw, is is correct that the isa irq's are always connected to the first
> > io apic? find_isa_irq_pin() doesn't handle that, and the caller just
> > access io apic 0.
>
> It appears it happens so for all systems checked so far. The MPS does
> not seem to enforce this configuration, so we might relax this
> dependency for flexibility. Note that not only find_isa_irq_pin()
> hardcodes this assumption -- setup_ExtINT_IRQ0_pin() does as well, for
> example.

(hm, dont we have an assert in there to catch ISA IRQs bound to the second
IO-APIC?) In any case, it would be a very surprising move if anyone added
a second IO-APIC for the sake of *ISA* devices. This would be truly
backwards.

Ingo

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

\
 
 \ /
  Last update: 2005-03-22 13:28    [W:0.059 / U:0.416 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site