From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763807AbYJJUVW (ORCPT ); Fri, 10 Oct 2008 16:21:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761248AbYJJUVO (ORCPT ); Fri, 10 Oct 2008 16:21:14 -0400 Received: from kroah.org ([198.145.64.141]:59698 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1760696AbYJJUVN (ORCPT ); Fri, 10 Oct 2008 16:21:13 -0400 Date: Fri, 10 Oct 2008 13:18:05 -0700 From: Greg KH To: Stefan Bader Cc: stable@kernel.org, Thomas Gleixner , Ingo Molnar , Yinghai Lu , linux-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: [stable] [PATCH] x86: Reserve FIRST_DEVICE_VECTOR in used_vectors bitmap Message-ID: <20081010201805.GC32164@kroah.com> References: <48EFB4B2.2020508@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48EFB4B2.2020508@canonical.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 10, 2008 at 04:01:54PM -0400, Stefan Bader wrote: > Affected: 2.6.24-2.6.27 > > Someone from the community found out, that after repeatedly unloading and > loading a device driver that uses MSI IRQs, the system eventually assigned > the vector initially reserved for IRQ0 to the device driver. > > The reason for this is, that although IRQ0 is tied to the FIRST_DEVICE_VECTOR > when declaring the irq_vector table, the corresponding bit in the used_vectors > map is not set. So, if vectors are released and assigned often enough, the > vector will get assigned to another interrupt. This happens more often with > MSI interrupts as those are exclusively using a vector. Is there a problem with being assigned to IRQ0 in situations like this? thanks, greg k-h