Patchworkβ [1/2] x86/PCI: for debuggability, show host bridge windows even when ignoring _CRS

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Submitter Bjorn Helgaas
Date 2009-11-04 17:39:13
Message ID <20091104173913.17517.30881.stgit@bob.kio>
Download mbox | patch
Permalink /patch/57709/
State Not Applicable
Headers show

Comments

Bjorn Helgaas - 2009-11-04 17:39:13
We have occasional problems with PCI resource allocation, and sometimes
they could be avoided by paying attention to what ACPI tells us about
the host bridges.  This patch doesn't change the behavior, but it prints
window information that should make debugging easier.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---
 arch/x86/pci/acpi.c |   26 ++++++++++++++++++--------
 1 files changed, 18 insertions(+), 8 deletions(-)


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Jesse Barnes - 2009-11-04 18:28:18
On Wed, 04 Nov 2009 10:39:13 -0700
Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:

> We have occasional problems with PCI resource allocation, and
> sometimes they could be avoided by paying attention to what ACPI
> tells us about the host bridges.  This patch doesn't change the
> behavior, but it prints window information that should make debugging
> easier.
> 
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Nice, applied these two to linux-next.

Patch

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 68b89dc..54db5a0 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -92,11 +92,12 @@  setup_resource(struct acpi_resource *acpi_res, void *data)
 	start = addr.minimum + addr.translation_offset;
 	end = start + addr.address_length - 1;
 	if (info->res_num >= max_root_bus_resources) {
-		printk(KERN_WARNING "PCI: Failed to allocate 0x%lx-0x%lx "
-			"from %s for %s due to _CRS returning more than "
-			"%d resource descriptors\n", (unsigned long) start,
-			(unsigned long) end, root->name, info->name,
-			max_root_bus_resources);
+		if (pci_probe & PCI_USE__CRS)
+			printk(KERN_WARNING "PCI: Failed to allocate "
+			       "0x%lx-0x%lx from %s for %s due to _CRS "
+			       "returning more than %d resource descriptors\n",
+			       (unsigned long) start, (unsigned long) end,
+			       root->name, info->name, max_root_bus_resources);
 		return AE_OK;
 	}
 
@@ -107,6 +108,12 @@  setup_resource(struct acpi_resource *acpi_res, void *data)
 	res->end = end;
 	res->child = NULL;
 
+	if (!(pci_probe & PCI_USE__CRS)) {
+		dev_printk(KERN_DEBUG, &info->bridge->dev,
+			   "host bridge window %pR (ignored)\n", res);
+		return AE_OK;
+	}
+
 	if (insert_resource(root, res)) {
 		dev_err(&info->bridge->dev,
 			"can't allocate host bridge window %pR\n", res);
@@ -132,6 +139,11 @@  get_current_resources(struct acpi_device *device, int busnum,
 	struct pci_root_info info;
 	size_t size;
 
+	if (!(pci_probe & PCI_USE__CRS))
+		dev_info(&device->dev,
+			 "ignoring host bridge windows from ACPI; "
+			 "boot with \"pci=use_crs\" to use them\n");
+
 	info.bridge = device;
 	info.bus = bus;
 	info.res_num = 0;
@@ -220,9 +232,7 @@  struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int do
 	} else {
 		bus = pci_create_bus(NULL, busnum, &pci_root_ops, sd);
 		if (bus) {
-			if (pci_probe & PCI_USE__CRS)
-				get_current_resources(device, busnum, domain,
-							bus);
+			get_current_resources(device, busnum, domain, bus);
 			bus->subordinate = pci_scan_child_bus(bus);
 		}
 	}