From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757295AbZAMITd (ORCPT ); Tue, 13 Jan 2009 03:19:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753754AbZAMITY (ORCPT ); Tue, 13 Jan 2009 03:19:24 -0500 Received: from vpn.id2.novell.com ([195.33.99.129]:45180 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751617AbZAMITX convert rfc822-to-8bit (ORCPT ); Tue, 13 Jan 2009 03:19:23 -0500 Message-Id: <496C5CBB.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.0 Date: Tue, 13 Jan 2009 08:19:55 +0000 From: "Jan Beulich" To: "Ingo Molnar" Cc: , , Subject: Re: x86: meaning of nolapic command line option References: <496790D1.76E4.0078.0@novell.com> <20090111024642.GA7077@elte.hu> In-Reply-To: <20090111024642.GA7077@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> Ingo Molnar 11.01.09 03:46 >>> > >* Jan Beulich wrote: > >> Shouldn't that option imply that all APIC related activity, including >> that relating to IO-APICs or PCI MSI, should be circumvented? I'm >> finding that MSI must be disabled separately, and while most of the >> IO-APIC stuff is indeed not happening, acpi_get_override_irq() only >> checks skip_ioapic_setup, but that doesn't normally set without the >> noapic command line option. >> >> Is there any reason pci_no_msi() and disable_ioapic_setup() shouldn't be >> called when !cpu_has_apic at the end of identify_cpu()? > >Yes, both depend on a lapic and they might limp on with whatever the BIOS >gave us, you are right that it should be disabled explicitly. Mind sending >a patch? I will - just wanted to see whether there's some hidden reason behind the current way this is coded. Actually, I meanwhile realized that doing this somply based on !cpu_has_apic wouldn't be right, it should (at least for 32-bits) also depend on APIC_INTEGRATED() - just like e.g. done in APIC_init_uniprocessor(). Jan