Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759248AbZFXT2c (ORCPT ); Wed, 24 Jun 2009 15:28:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751633AbZFXT2Z (ORCPT ); Wed, 24 Jun 2009 15:28:25 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:52509 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751849AbZFXT2Y (ORCPT ); Wed, 24 Jun 2009 15:28:24 -0400 Date: Wed, 24 Jun 2009 12:28:13 -0700 From: Gary Hade To: Jaswinder Singh Rajput Cc: Gary Hade , Thomas Gleixner , Larry Finger , Jesse Barnes , LKML , Ingo Molnar , x86 maintainers , Len Brown , Linus Torvalds Subject: Re: Regression with commit f9cde5f in 2.6.30-gitX Message-ID: <20090624192813.GF7239@us.ibm.com> References: <4A418254.9050607@lwfinger.net> <1245845787.3093.3.camel@localhost.localdomain> <4A423686.8050905@lwfinger.net> <1245859068.3216.5.camel@localhost.localdomain> <20090624161306.GC7239@us.ibm.com> <1245861219.3216.15.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1245861219.3216.15.camel@localhost.localdomain> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4363 Lines: 117 On Wed, Jun 24, 2009 at 10:03:39PM +0530, Jaswinder Singh Rajput wrote: > On Wed, 2009-06-24 at 09:13 -0700, Gary Hade wrote: > > On Wed, Jun 24, 2009 at 09:27:48PM +0530, Jaswinder Singh Rajput wrote: > > > On Wed, 2009-06-24 at 17:19 +0200, Thomas Gleixner wrote: > > > > Larry, > > > > > > > > On Wed, 24 Jun 2009, Larry Finger wrote: > > > > > For the record, the printout from the patch results in the following: > > > > > > > > > > PCI: Failed to allocate 0xd0000-0xd3fff from PCI mem for PCI Bus 0000:00 > > > > > PCI: Failed to allocate 0xec000-0xeffff from PCI mem for PCI Bus > > > > > 0000:00 due to _CRS returning more than 13 resource descriptors > > > > > PCI: Failed to allocate 0xf0000-0xfffff from PCI mem for PCI Bus > > > > > 0000:00 due to _CRS returning more than 13 resource descriptors > > > > > PCI: Failed to allocate 0xc0000000-0xfebfffff from PCI mem for PCI Bus > > > > > 0000:00 due to _CRS returning more than 13 resource descriptors > > > > > > > > can you please the patch below instead of the other one ? > > > > > > > > Thanks, > > > > > > > > tglx > > > > --- > > > > diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c > > > > index 16c3fda..39a0cce 100644 > > > > --- a/arch/x86/pci/acpi.c > > > > +++ b/arch/x86/pci/acpi.c > > > > @@ -99,7 +99,6 @@ setup_resource(struct acpi_resource *acpi_res, void *data) > > > > "%d resource descriptors\n", (unsigned long) res->start, > > > > (unsigned long) res->end, root->name, info->name, > > > > max_root_bus_resources); > > > > - info->res_num++; > > > > return AE_OK; > > > > } > > > > > > > > > > This fails and system does not boot, I already tested this patch 8 hours > > > ago. > > > > I think the resource array needs to be larger. Can you try > > the below patch? > > > > Gary > > > > --- linux-2.6.30-rc8/include/linux/pci.h.ORIG 2009-06-24 09:03:41.000000000 -0700 > > +++ linux-2.6.30-rc8/include/linux/pci.h 2009-06-24 09:06:50.000000000 -0700 > > @@ -319,7 +319,7 @@ static inline void pci_add_saved_cap(str > > } > > > > #ifndef PCI_BUS_NUM_RESOURCES > > -#define PCI_BUS_NUM_RESOURCES 16 > > +#define PCI_BUS_NUM_RESOURCES 20 > > #endif > > > > #define PCI_REGION_FLAG_MASK 0x0fU /* These bits of resource flags tell us the PCI region flags */ > > > Larry already suggested PCI_BUS_NUM_RESOURCES to 24 in his patch (check > first reply from him). Sorry I missed that. > > Then what is the point of removing last 3 and then adding 3 or more > resources, so patch f9cde5f lost its purpose, The reason for not populating the last 3 slots of the resource array when there is a transparent bridge on the bus is to make sure devices downstream of the transparent bridge get the resources they need. Because of the offset of 3 between the transparent bridge parent and child bus resource arrays established by if (dev->transparent) { dev_info(&dev->dev, "transparent bridge\n"); for(i = 3; i < PCI_BUS_NUM_RESOURCES; i++) child->resource[i] = child->parent->resource[i - 3]; } in pci_read_bridge_bases() [drivers/pci/probe.c] and refreshed by similar in adjust_transparent_bridge_resources() [arch/x86/pci/acpi.c] the transparent bridge child bus resource array will not reference the resources in those last 3 slots. > best case will be to > revert f9cde5f as it also removed : > > if (info->res_num >= PCI_BUS_NUM_RESOURCES) > return AE_OK; > > which is required in any case. In the case of a root bus without a transparent bridge, this still exists (w/added warning and resource count increment) as if (info->res_num >= max_root_bus_resources) { < warn and increment resource count > return AE_OK; } because max_root_bus_resources==PCI_BUS_NUM_RESOURCES In the case were there is a transparent bridge on the root bus, 'max_root_bus_resources' needs to be 3 less than PCI_BUS_NUM_RESOURCES to avoid populating the last 3 slots of the array that are not visible below the transparent bridge. Gary -- Gary Hade System x Enablement IBM Linux Technology Center 503-578-4503 IBM T/L: 775-4503 garyhade@us.ibm.com http://www.ibm.com/linux/ltc -- 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/