From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261265AbUBTTH7 (ORCPT ); Fri, 20 Feb 2004 14:07:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261369AbUBTTHr (ORCPT ); Fri, 20 Feb 2004 14:07:47 -0500 Received: from mail.kroah.org ([65.200.24.183]:63717 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S261265AbUBTTGW convert rfc822-to-8bit (ORCPT ); Fri, 20 Feb 2004 14:06:22 -0500 Subject: Re: [PATCH] PCI update for 2.6.3 In-Reply-To: <10773039813376@kroah.com> X-Mailer: gregkh_patchbomb Date: Fri, 20 Feb 2004 11:06:21 -0800 Message-Id: <10773039813517@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: linux-kernel@vger.kernel.org, pcihpd-discuss@lists.sourceforge.net Content-Transfer-Encoding: 7BIT From: Greg KH Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org ChangeSet 1.1580, 2004/02/20 09:20:38-08:00, Martine.Silbermann@hp.com [PATCH] PCI: update MSI Documentation After getting feedback from Tom,I made some changes to the patch Attached is a revised version. Documentation/MSI-HOWTO.txt | 19 +++++++++---------- 1 files changed, 9 insertions(+), 10 deletions(-) diff -Nru a/Documentation/MSI-HOWTO.txt b/Documentation/MSI-HOWTO.txt --- a/Documentation/MSI-HOWTO.txt Fri Feb 20 10:44:24 2004 +++ b/Documentation/MSI-HOWTO.txt Fri Feb 20 10:44:24 2004 @@ -1,6 +1,8 @@ The MSI Driver Guide HOWTO Tom L Nguyen tom.l.nguyen@intel.com 10/03/2003 + Revised Feb 12, 2004 by Martine Silbermann + email: Martine.Silbermann@hp.com 1. About this guide @@ -90,17 +92,14 @@ 5. Configuring a driver to use MSI/MSI-X By default, the kernel will not enable MSI/MSI-X on all devices that -support this capability once the patch is installed. A kernel -configuration option must be selected to enable MSI/MSI-X support. +support this capability. The CONFIG_PCI_USE_VECTOR kernel option +must be selected to enable MSI/MSI-X support. 5.1 Including MSI support into the kernel -To include MSI support into the kernel requires users to patch the -VECTOR-base patch first and then the MSI patch because the MSI -support needs VECTOR based scheme. Once these patches are installed, -setting CONFIG_PCI_USE_VECTOR enables the VECTOR based scheme and -the option for MSI-capable device drivers to selectively enable MSI -(using pci_enable_msi as desribed below). +To allow MSI-Capable device drivers to selectively enable MSI (using +pci_enable_msi as described below), the VECTOR based scheme needs to +be enabled by setting CONFIG_PCI_USE_VECTOR. Since the target of the inbound message is the local APIC, providing CONFIG_PCI_USE_VECTOR is dependent on whether CONFIG_X86_LOCAL_APIC @@ -130,7 +129,7 @@ 5.2 Configuring for MSI support Due to the non-contiguous fashion in vector assignment of the -existing Linux kernel, this patch does not support multiple +existing Linux kernel, this version does not support multiple messages regardless of the device function is capable of supporting more than one vector. The bus driver initializes only entry 0 of this capability if pci_enable_msi(...) is called successfully by @@ -232,7 +231,7 @@ CONFIG_X86_LOCAL_APIC. Once CONFIG_X86_LOCAL_APIC=y, setting CONFIG_PCI_USE_VECTOR enables the VECTOR based scheme and the option for MSI-capable device drivers to selectively enable -MSI (using pci_enable_msi as desribed below). +MSI (using pci_enable_msi as described below). Note that CONFIG_X86_IO_APIC setting is irrelevant because MSI vector is allocated new during runtime and MSI support does not