[PATCH 2.6.16.18] MSI: Proposed fix for MSI/MSI-X load failure

[Ravinandan Arakali]

Hi,
This patch suggests a fix for the MSI/MSI-X load failure.

Please review the patch.

Symptoms:
When a driver is loaded with MSI followed by MSI-X, the load fails indicating 
that the MSI vector is still active. And vice versa.

Suspected rootcause:
This happens inspite of driver calling free_irq() followed by 
pci_disable_msi/pci_disable_msix. This appears to be a kernel bug 
wherein the pci_disable_msi and pci_disable_msix calls do not 
clear/unpopulate the msi_desc data structure that was populated 
by pci_enable_msi/pci_enable_msix.

Proposed fix:
Free the MSI vector in pci_disable_msi and all allocated MSI-X vectors 
in pci_disable_msix.

Testing:
The fix has been tested on IA64 platforms with Neterion's Xframe driver.

Signed-off-by: Ravinandan Arakali <ravinandan.arakali@xxxxxxxxxxxx>
---

diff -urpN old/drivers/pci/msi.c new/drivers/pci/msi.c
--- old/drivers/pci/msi.c	2006-05-31 19:02:19.000000000 -0700
+++ new/drivers/pci/msi.c	2006-05-31 19:02:39.000000000 -0700
@@ -779,6 +779,7 @@ void pci_disable_msi(struct pci_dev* dev
 		nr_released_vectors++;
 		default_vector = entry->msi_attrib.default_vector;
 		spin_unlock_irqrestore(&msi_lock, flags);
+		msi_free_vector(dev, dev->irq, 1);
 		/* Restore dev->irq to its default pin-assertion vector */
 		dev->irq = default_vector;
 		disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
@@ -1046,6 +1047,7 @@ void pci_disable_msix(struct pci_dev* de
 
 		}
 	}
+	msi_remove_pci_irq_vectors(dev);
 }
 
 /**

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