Messages in this thread | | | Date | Wed, 24 Jun 2009 12:28:13 -0700 | From | Gary Hade <> | Subject | Re: Regression with commit f9cde5f in 2.6.30-gitX |
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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
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