pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2

[PATCH 2/2] pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2

this change

| commit 23a274c8a5adafc74a66f16988776fc7dd6f6e51
| Author: Prakash, Sathya <sathya.prakash@lsi.com>
| Date:   Fri Mar 7 15:53:21 2008 +0530
|
|     [SCSI] mpt fusion: Enable MSI by default for SAS controllers
|
|     This patch modifies the driver to enable MSI by default for all SAS chips.
|
|     Signed-off-by: Sathya Prakash <sathya.prakash@lsi.com>
|     Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
|
Causes the kexec of a RHEL 5.1 kernel to fail.

root casue: the rhel 5.1 kernel still uses INTx emulation.  and
mptscsih_shutdown doesn't call pci_disable_msi to reenable INTx on kexec path

So call pci_msi_shutdown in the shutdown path to do the same thing to msix

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@hobbes.lan>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index e3a05cc..8c61304c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -571,10 +571,9 @@
 }
 EXPORT_SYMBOL(pci_enable_msi);
 
-void pci_disable_msi(struct pci_dev* dev)
+void pci_msi_shutdown(struct pci_dev* dev)
 {
 	struct msi_desc *entry;
-	int default_irq;
 
 	if (!pci_msi_enable || !dev || !dev->msi_enabled)
 		return;
@@ -590,15 +589,26 @@
 		u32 mask = entry->msi_attrib.maskbits_mask;
 		msi_set_mask_bits(dev->irq, mask, ~mask);
 	}
-	if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {
+	if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI)
 		return;
-	}
-
-	default_irq = entry->msi_attrib.default_irq;
-	msi_free_irqs(dev);
 
 	/* Restore dev->irq to its default pin-assertion irq */
-	dev->irq = default_irq;
+	dev->irq = entry->msi_attrib.default_irq;
+}
+void pci_disable_msi(struct pci_dev* dev)
+{
+	struct msi_desc *entry;
+
+	if (!pci_msi_enable || !dev || !dev->msi_enabled)
+		return;
+
+	pci_msi_shutdown(dev);
+
+	entry = list_entry(dev->msi_list.next, struct msi_desc, list);
+	if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI)
+		return;
+
+	msi_free_irqs(dev);
 }
 EXPORT_SYMBOL(pci_disable_msi);
 
@@ -691,7 +701,7 @@
 	msi_free_irqs(dev);
 }
 
-void pci_disable_msix(struct pci_dev* dev)
+void pci_msix_shutdown(struct pci_dev* dev)
 {
 	if (!pci_msi_enable || !dev || !dev->msix_enabled)
 		return;
@@ -699,6 +709,13 @@
 	msix_set_enable(dev, 0);
 	pci_intx_for_msi(dev, 1);
 	dev->msix_enabled = 0;
+}
+void pci_disable_msix(struct pci_dev* dev)
+{
+	if (!pci_msi_enable || !dev || !dev->msix_enabled)
+		return;
+
+	pci_msix_shutdown(dev);
 
 	msix_free_all_irqs(dev);
 }