From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 2 Feb 2001 12:49:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 2 Feb 2001 12:49:20 -0500 Received: from nat-pool.corp.redhat.com ([199.183.24.200]:12083 "EHLO devserv.devel.redhat.com") by vger.kernel.org with ESMTP id ; Fri, 2 Feb 2001 12:49:05 -0500 Date: Fri, 2 Feb 2001 12:45:43 -0500 (EST) From: Ingo Molnar X-X-Sender: To: "Maciej W. Rozycki" cc: Manfred , Subject: Re: mpparse.c question In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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/