Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422645AbWBNQvA (ORCPT ); Tue, 14 Feb 2006 11:51:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422647AbWBNQu7 (ORCPT ); Tue, 14 Feb 2006 11:50:59 -0500 Received: from [194.90.237.34] ([194.90.237.34]:38712 "EHLO mtlexch01.mtl.com") by vger.kernel.org with ESMTP id S1422645AbWBNQu7 (ORCPT ); Tue, 14 Feb 2006 11:50:59 -0500 Date: Tue, 14 Feb 2006 18:52:22 +0200 From: "Michael S. Tsirkin" To: Roland Dreier Cc: gregkh@suse.de, linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz Subject: Re: AMD 8131 and MSI quirk Message-ID: <20060214165222.GC12974@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: <524q799p2t.fsf@cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <524q799p2t.fsf@cisco.com> User-Agent: Mutt/1.4.2.1i X-OriginalArrivalTime: 14 Feb 2006 16:52:49.0703 (UTC) FILETIME=[16A70B70:01C63187] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4207 Lines: 112 Quoting r. Roland Dreier : > Subject: AMD 8131 and MSI quirk > > The current quirk_amd_8131_ioapic() function sets a global > pci_msi_quirk flag, which disables MSI/MSI-X for all devices in the > system. This is safe but suboptimal, because there may be devices on > other buses not related to the AMD 8131 bridge, for which MSI would > work fine. As an example, see the end of this email for a lspci -t > from a real Opteron system that has PCI-X buses coming from an AMD > 8131 and PCI Express buses coming from an Nforce4 bridge -- MSI works > fine for the Mellanox InfiniBand adapter on the PCIe bus, if we allow > it to be enabled. The following should do this IMO. Roland, could you test this patch please? --- It turns out AMD 8131 quirk only affects MSI for devices behind the 8131 bridge. Handle this by adding a flags field in pci_bus, inherited from parent to child. Signed-off-by: Michael S. Tsirkin Index: linux-2.6.16-rc2/drivers/pci/msi.c =================================================================== --- linux-2.6.16-rc2.orig/drivers/pci/msi.c 2006-02-14 17:09:23.000000000 +0200 +++ linux-2.6.16-rc2/drivers/pci/msi.c 2006-02-14 18:14:00.000000000 +0200 @@ -699,6 +699,9 @@ int pci_enable_msi(struct pci_dev* dev) if (dev->no_msi) return status; + if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MSI) + return -EINVAL; + temp = dev->irq; if ((status = msi_init()) < 0) @@ -924,6 +927,9 @@ int pci_enable_msix(struct pci_dev* dev, if (!pci_msi_enable || !dev || !entries) return -EINVAL; + if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MSI) + return -EINVAL; + if ((status = msi_init()) < 0) return status; Index: linux-2.6.16-rc2/drivers/pci/probe.c =================================================================== --- linux-2.6.16-rc2.orig/drivers/pci/probe.c 2006-02-14 17:09:23.000000000 +0200 +++ linux-2.6.16-rc2/drivers/pci/probe.c 2006-02-14 17:58:17.000000000 +0200 @@ -347,6 +347,7 @@ pci_alloc_child_bus(struct pci_bus *pare child->parent = parent; child->ops = parent->ops; child->sysdata = parent->sysdata; + child->bus_flags = parent->bus_flags; child->bridge = get_device(&bridge->dev); child->class_dev.class = &pcibus_class; Index: linux-2.6.16-rc2/drivers/pci/quirks.c =================================================================== --- linux-2.6.16-rc2.orig/drivers/pci/quirks.c 2006-02-14 17:09:23.000000000 +0200 +++ linux-2.6.16-rc2/drivers/pci/quirks.c 2006-02-14 17:58:17.000000000 +0200 @@ -575,8 +575,11 @@ static void __init quirk_amd_8131_ioapic { unsigned char revid, tmp; - pci_msi_quirk = 1; - printk(KERN_WARNING "PCI: MSI quirk detected. pci_msi_quirk set.\n"); + if (dev->subordinate) { + printk(KERN_WARNING "PCI: MSI quirk detected. " + "PCI_BUS_FLAGS_NO_MSI set for subordinate bus.\n"); + dev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI; + } if (nr_ioapics == 0) return; Index: linux-2.6.16-rc2/include/linux/pci.h =================================================================== --- linux-2.6.16-rc2.orig/include/linux/pci.h 2006-02-14 17:09:24.000000000 +0200 +++ linux-2.6.16-rc2/include/linux/pci.h 2006-02-14 17:58:17.000000000 +0200 @@ -95,6 +95,11 @@ enum pci_channel_state { pci_channel_io_perm_failure = (__force pci_channel_state_t) 3, }; +typedef unsigned short __bitwise pci_bus_flags_t; +enum pci_bus_flags { + PCI_BUS_FLAGS_NO_MSI = (pci_bus_flags_t) 1, +}; + /* * The pci_dev structure is used to describe PCI devices. */ @@ -203,7 +208,7 @@ struct pci_bus { char name[48]; unsigned short bridge_ctl; /* manage NO_ISA/FBB/et al behaviors */ - unsigned short pad2; + pci_bus_flags_t bus_flags; /* Inherited by child busses */ struct device *bridge; struct class_device class_dev; struct bin_attribute *legacy_io; /* legacy I/O for this bus */ -- Michael S. Tsirkin Staff Engineer, Mellanox Technologies - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/