[PATCH] PCI: 6700/6702PXH quirk

On the 6700/6702 PXH part, a MSI may get corrupted if an ACPI hotplug
driver and SHPC driver in MSI mode are used together.

This patch will prevent MSI from being enabled for the SHPC as part of
an early pci quirk, as well as on any pci device which sets the no_msi
bit.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 26 insertions, 2 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index b5ab9aa6ff7c..2b85aa39f954 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -453,7 +453,7 @@ static void enable_msi_mode(struct pci_dev *dev, int pos, int type)
         }
 }
 
-static void disable_msi_mode(struct pci_dev *dev, int pos, int type)
+void disable_msi_mode(struct pci_dev *dev, int pos, int type)
 {
         u16 control;
 
@@ -699,6 +699,9 @@ int pci_enable_msi(struct pci_dev* dev)
         if (!pci_msi_enable || !dev)
                 return status;
 
+        if (dev->no_msi)
+                return status;
+
         temp = dev->irq;
 
         if ((status = msi_init()) < 0)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d94d7af4f7a0..fa36094aa0f9 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -46,7 +46,7 @@ extern int pci_msi_quirk;
 #else
 #define pci_msi_quirk 0
 #endif
-
+void disable_msi_mode(struct pci_dev *dev, int pos, int type);
 extern int pcie_mch_quirk;
 extern struct device_attribute pci_dev_attrs[];
 extern struct class_device_attribute class_device_attr_cpuaffinity;
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a9160ad16581..bb36bb69803f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1291,6 +1291,27 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_E7520_MCH,	quir
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_E7320_MCH,  quirk_pcie_mch );
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_E7525_MCH,  quirk_pcie_mch );
 
+
+/*
+ * It's possible for the MSI to get corrupted if shpc and acpi
+ * are used together on certain PXH-based systems.
+ */
+static void __devinit quirk_pcie_pxh(struct pci_dev *dev)
+{
+        disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
+                                        PCI_CAP_ID_MSI);
+        dev->no_msi = 1;
+
+        printk(KERN_WARNING "PCI: PXH quirk detected, "
+                "disabling MSI for SHPC device\n");
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXHD_0,     quirk_pcie_pxh);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXHD_1,     quirk_pcie_pxh);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXH_0,      quirk_pcie_pxh);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXH_1,      quirk_pcie_pxh);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXHV,       quirk_pcie_pxh);
+
+
 static void __devinit quirk_netmos(struct pci_dev *dev)
 {
         unsigned int num_parallel = (dev->subsystem_device & 0xf0) >> 4;