[patch 0/2] PNP: disable PNP motherboard resources that overlap PCI BARs

[patch 0/2] PNP: disable PNP motherboard resources that overlap PCI BARs

[Bjorn Helgaas]

The following two patches fix several problems caused by BIOSes that
report PNP motherboard device resources that overlap with PCI BARs.

I think these should go in before 2.6.25 because some of these problems
showed up in 2.6.24 when we increased PNP_MAX_MEM from 4 to 12, and
there's no good way to work around them.

Bjorn
-- 

[patch 1/2] PNP: revert Supermicro H8DCE motherboard quirk

[Bjorn Helgaas]

[-- Attachment #1: pnp-remove-supermicro-quirk --]
[-- Type: text/plain, Size: 2325 bytes --]

There are other systems with similar problems
(http://lkml.org/lkml/2008/1/27/168), so we need a more
generic quirk.  Remove the Supermicro-specific one first.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work7/drivers/pnp/quirks.c
===================================================================
--- work7.orig/drivers/pnp/quirks.c	2008-02-27 10:17:19.000000000 -0700
+++ work7/drivers/pnp/quirks.c	2008-02-27 10:17:40.000000000 -0700
@@ -17,7 +17,6 @@
 #include <linux/slab.h>
 #include <linux/pnp.h>
 #include <linux/io.h>
-#include <linux/dmi.h>
 #include <linux/kallsyms.h>
 #include "base.h"
 
@@ -109,46 +108,6 @@
 		       "pnp: SB audio device quirk - increasing port range\n");
 }
 
-static void quirk_supermicro_h8dce_system(struct pnp_dev *dev)
-{
-	int i;
-	static struct dmi_system_id supermicro_h8dce[] = {
-		{
-			.ident = "Supermicro H8DCE",
-			.matches = {
-				DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
-				DMI_MATCH(DMI_PRODUCT_NAME, "H8DCE"),
-			},
-		},
-		{ }
-	};
-
-	if (!dmi_check_system(supermicro_h8dce))
-		return;
-
-	/*
-	 * On the Supermicro H8DCE, there's a system device with resources
-	 * that overlap BAR 6 of the built-in SATA PCI adapter.  If the PNP
-	 * system device claims them, the sata_nv driver won't be able to.
-	 * More details at:
-	 *     https://bugzilla.redhat.com/show_bug.cgi?id=280641
-	 *     https://bugzilla.redhat.com/show_bug.cgi?id=313491
-	 *     http://lkml.org/lkml/2008/1/9/449
-	 *     http://thread.gmane.org/gmane.linux.acpi.devel/27312
-	 */
-	for (i = 0; i < PNP_MAX_MEM; i++) {
-		if (pnp_mem_valid(dev, i) && pnp_mem_len(dev, i) &&
-		    (pnp_mem_start(dev, i) & 0xdfef0000) == 0xdfef0000) {
-			dev_warn(&dev->dev, "disabling 0x%llx-0x%llx to prevent"
-				" conflict with sata_nv PCI device\n",
-				(unsigned long long) pnp_mem_start(dev, i),
-				(unsigned long long) (pnp_mem_start(dev, i) +
-					pnp_mem_len(dev, i) - 1));
-			pnp_mem_flags(dev, i) = 0;
-		}
-	}
-}
-
 /*
  *  PnP Quirks
  *  Cards or devices that need some tweaking due to incomplete resource info
@@ -169,8 +128,6 @@
 	{"CTL0043", quirk_sb16audio_resources},
 	{"CTL0044", quirk_sb16audio_resources},
 	{"CTL0045", quirk_sb16audio_resources},
-	{"PNP0c01", quirk_supermicro_h8dce_system},
-	{"PNP0c02", quirk_supermicro_h8dce_system},
 	{""}
 };
 

-- 

[patch 2/2] PNP: disable PNP motherboard resources that overlap PCI BARs

[Bjorn Helgaas]

[-- Attachment #1: pnp-system-quirk --]
[-- Type: text/plain, Size: 3821 bytes --]

Some BIOSes have PNP motherboard devices with resources that
partially overlap PCI BARs.  The PNP system driver claims these
motherboard resources, which prevents the normal PCI driver from
requesting them later.

This patch disables the PNP resources that conflict with PCI BARs
so they won't be claimed by the PNP system driver.

Of course, this only works if PCI devices have already been enumerated.
Currently this is the case because PCI devices are discovered before
any PNP init via this path:

    acpi_pci_root_init() -> acpi_pci_root_add() -> pci_acpi_scan_root() ->
	pci_scan_bus_parented() -> pci_scan_child_bus() -> ...

Avuton Olrich tested this and confirmed that it fixes his ALSA sound
card (see http://lkml.org/lkml/2008/1/27/168).

References:
    https://bugzilla.redhat.com/show_bug.cgi?id=280641
    https://bugzilla.redhat.com/show_bug.cgi?id=313491
    http://lkml.org/lkml/2008/1/9/449
    http://thread.gmane.org/gmane.linux.acpi.devel/27312
    http://lkml.org/lkml/2008/1/27/168

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work7/drivers/pnp/quirks.c
===================================================================
--- work7.orig/drivers/pnp/quirks.c	2008-03-06 15:40:51.000000000 -0700
+++ work7/drivers/pnp/quirks.c	2008-03-06 15:40:52.000000000 -0700
@@ -108,6 +108,77 @@
 		       "pnp: SB audio device quirk - increasing port range\n");
 }
 
+
+#include <linux/pci.h>
+
+static void quirk_system_pci_resources(struct pnp_dev *dev)
+{
+	struct pci_dev *pdev = NULL;
+	resource_size_t pnp_start, pnp_end, pci_start, pci_end;
+	int i, j;
+
+	/*
+	 * Some BIOSes have PNP motherboard devices with resources that
+	 * partially overlap PCI BARs.  The PNP system driver claims these
+	 * motherboard resources, which prevents the normal PCI driver from
+	 * requesting them later.
+	 *
+	 * This patch disables the PNP resources that conflict with PCI BARs
+	 * so they won't be claimed by the PNP system driver.
+	 */
+	for_each_pci_dev(pdev) {
+		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+			if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM) ||
+			    pci_resource_len(pdev, i) == 0)
+				continue;
+
+			pci_start = pci_resource_start(pdev, i);
+			pci_end = pci_resource_end(pdev, i);
+			for (j = 0; j < PNP_MAX_MEM; j++) {
+				if (!pnp_mem_valid(dev, j) ||
+				    pnp_mem_len(dev, j) == 0)
+					continue;
+
+				pnp_start = pnp_mem_start(dev, j);
+				pnp_end = pnp_mem_end(dev, j);
+
+				/*
+				 * If the PNP region doesn't overlap the PCI
+				 * region at all, there's no problem.
+				 */
+				if (pnp_end < pci_start || pnp_start > pci_end)
+					continue;
+
+				/*
+				 * If the PNP region completely encloses (or is
+				 * at least as large as) the PCI region, that's
+				 * also OK.  For example, this happens when the
+				 * PNP device describes a bridge with PCI
+				 * behind it.
+				 */
+				if (pnp_start <= pci_start &&
+				    pnp_end >= pci_end)
+					continue;
+
+				/*
+				 * Otherwise, the PNP region overlaps *part* of
+				 * the PCI region, and that might prevent a PCI
+				 * driver from requesting its resources.
+				 */
+				dev_warn(&dev->dev, "mem resource "
+					"(0x%llx-0x%llx) overlaps %s BAR %d "
+					"(0x%llx-0x%llx), disabling\n",
+					(unsigned long long) pnp_start,
+					(unsigned long long) pnp_end,
+					pci_name(pdev), i,
+					(unsigned long long) pci_start,
+					(unsigned long long) pci_end);
+				pnp_mem_flags(dev, j) = 0;
+			}
+		}
+	}
+}
+
 /*
  *  PnP Quirks
  *  Cards or devices that need some tweaking due to incomplete resource info
@@ -128,6 +199,8 @@
 	{"CTL0043", quirk_sb16audio_resources},
 	{"CTL0044", quirk_sb16audio_resources},
 	{"CTL0045", quirk_sb16audio_resources},
+	{"PNP0c01", quirk_system_pci_resources},
+	{"PNP0c02", quirk_system_pci_resources},
 	{""}
 };
 

-- 

Re: [patch 0/2] PNP: disable PNP motherboard resources that overlap PCI BARs

[Thomas Renninger]

On Tue, 2008-03-11 at 15:24 -0600, Bjorn Helgaas wrote:
> The following two patches fix several problems caused by BIOSes that
> report PNP motherboard device resources that overlap with PCI BARs.
> 
> I think these should go in before 2.6.25 because some of these problems
> showed up in 2.6.24 when we increased PNP_MAX_MEM from 4 to 12, and
> there's no good way to work around them.

I cannot judge about the "cleanness" because of possible changes of
initialization time of pci/pnp or whatever.

I can confirm that ACPI resource declarations (especially (only?) in the
general motherboard devices) are often rather broken.
Therefore I like your general approach compared to the per machine dmi
match quirks. I expect the latter (dmi matching) is rather hopeless.


   Thomas