Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759463AbZCRWlW (ORCPT ); Wed, 18 Mar 2009 18:41:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758235AbZCRWjt (ORCPT ); Wed, 18 Mar 2009 18:39:49 -0400 Received: from g1t0029.austin.hp.com ([15.216.28.36]:27660 "EHLO g1t0029.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755816AbZCRWjs (ORCPT ); Wed, 18 Mar 2009 18:39:48 -0400 From: Alex Chiang Subject: [PATCH v4 04/12] PCI: always scan child buses To: jbarnes@virtuousgeek.org Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Alex Chiang Date: Wed, 18 Mar 2009 16:39:46 -0600 Message-ID: <20090318223946.887.62372.stgit@bob.kio> In-Reply-To: <20090318222426.887.1008.stgit@bob.kio> References: <20090318222426.887.1008.stgit@bob.kio> User-Agent: StGIT/0.14.3.215.gff3d MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2904 Lines: 82 While scanning bridges, we stop our scan if we encounter a bus that we've seen before, to work around some buggy chipsets. This is a good idea, but prevents us from fully scanning the PCI bus at a future time (to find newly hot-added devices, for example). Change the logic so that we skip _re-adding_ an existing bus that we've seen before, but also allow the scan to descend to all child buses. Now that we're potentially scanning our child buses again, we also need to be sure not to attempt re-initializing their BARs so we avoid that. This patch lays the groundwork to allow the user to issue a rescan of the PCI bus at any time. Signed-off-by: Alex Chiang --- drivers/pci/probe.c | 33 +++++++++++++++++++-------------- 1 files changed, 19 insertions(+), 14 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index d392813..a3959ce 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -511,21 +511,21 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, /* * If we already got to this bus through a different bridge, - * ignore it. This can happen with the i450NX chipset. + * don't re-add it. This can happen with the i450NX chipset. + * + * However, we continue to descend down the hierarchy and + * scan remaining child buses. */ - if (pci_find_bus(pci_domain_nr(bus), busnr)) { - dev_info(&dev->dev, "bus %04x:%02x already known\n", - pci_domain_nr(bus), busnr); - goto out; + child = pci_find_bus(pci_domain_nr(bus), busnr); + if (!child) { + child = pci_add_new_bus(bus, dev, busnr); + if (!child) + goto out; + child->primary = buses & 0xFF; + child->subordinate = (buses >> 16) & 0xFF; + child->bridge_ctl = bctl; } - child = pci_add_new_bus(bus, dev, busnr); - if (!child) - goto out; - child->primary = buses & 0xFF; - child->subordinate = (buses >> 16) & 0xFF; - child->bridge_ctl = bctl; - cmax = pci_scan_child_bus(child); if (cmax > max) max = cmax; @@ -1075,8 +1075,13 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus) * After performing arch-dependent fixup of the bus, look behind * all PCI-to-PCI bridges on this bus. */ - pr_debug("PCI: Fixups for bus %04x:%02x\n", pci_domain_nr(bus), bus->number); - pcibios_fixup_bus(bus); + if (!bus->is_added) { + pr_debug("PCI: Fixups for bus %04x:%02x\n", pci_domain_nr(bus), bus->number); + pcibios_fixup_bus(bus); + if (pci_is_root_bus(bus)) + bus->is_added = 1; + } + for (pass=0; pass < 2; pass++) list_for_each_entry(dev, &bus->devices, bus_list) { if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || -- 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/