From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264983AbTIIWSU (ORCPT ); Tue, 9 Sep 2003 18:18:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264918AbTIIWPX (ORCPT ); Tue, 9 Sep 2003 18:15:23 -0400 Received: from hermes.py.intel.com ([146.152.216.3]:64453 "EHLO hermes.py.intel.com") by vger.kernel.org with ESMTP id S264894AbTIIWO2 convert rfc822-to-8bit (ORCPT ); Tue, 9 Sep 2003 18:14:28 -0400 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT X-MimeOLE: Produced By Microsoft Exchange V6.0.6375.0 Subject: RE: MSI fix for buggy PCI/PCI-X hardware Date: Tue, 9 Sep 2003 15:14:19 -0700 Message-ID: <7F740D512C7C1046AB53446D3720017304AF29@scsmsx402.sc.intel.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: MSI fix for buggy PCI/PCI-X hardware Thread-Index: AcN3Af2kPa+4pLmfRZ+ny4cs/G+UbwAGBVQQ From: "Nakajima, Jun" To: "Jeff Garzik" , "long" Cc: , , "Nguyen, Tom L" , X-OriginalArrivalTime: 09 Sep 2003 22:14:20.0540 (UTC) FILETIME=[B7A76BC0:01C3771F] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeff, Hi. How about the default behavior? I'm not a fan of disable_msi(), because we need to update the driver as we find problems, and we cannot predict which PCI/PCI-X devices in the world have such a problem, although we know some will. The workaround in drivers/pci/quirk.c is much better, compared to modifying the driver, but we still need to update the file (and rebuild the kernel) as we find problems. In my opinion, we might want to use drivers/pci/quirk.c to blacklist PCI Express devices if any (hope not). For PCI/PCI-X devices, we might want to enable MSI once verified for it. To that end we can also use drivers/pci/quirk.c to whitelist them (or it's abuse?). That way we can avoid situations like "it hangs, it does not get interrupts", "disable ACPI, oh no, MSI". Thanks, Jun > -----Original Message----- > From: Jeff Garzik [mailto:jgarzik@pobox.com] > Sent: Tuesday, September 09, 2003 11:41 AM > To: long > Cc: linux-kernel@vger.kernel.org; greg@kroah.com; Nakajima, Jun; Nguyen, > Tom L; zwane@linuxpower.ca > Subject: Re: MSI fix for buggy PCI/PCI-X hardware > > On Tue, Sep 09, 2003 at 08:39:37AM -0700, long wrote: > > The proposed solution is to provide a new API, named "int > > disable_msi(struct pci_dev *dev)", to allow IHV's who have > > shipped PCI/PCI-X hardware that does not work in MSI mode to update > > their software drivers to request the kernel to switch the > > interrupt mode from MSI mode back to IRQ pin-assertion mode. > > No need for a new API. We have drivers/pci/quirk.c where we add PCI > devices with known bugs. If there is commonality of the bugs across > hardware, we can easily add a common "quirk" which fixes the situation. > > Individual drivers shouldn't need to bother with this, really. > > As an aside, if you need to blacklist certain _systems_ rather than > certain PCI devices, you should either modify drivers/pci/quirks.c or > arch/i386/kernel/dmi_scan.c. > > Jeff > >