[PATCH] x86, irq: Keep IRQ assignment for PCI devices during suspend/hibernation

[Jiang Liu <jiang.liu@linux.intel.com>]

Function pci_disable_device() may be called for PCI devices during
suspend/hibernation, which in turn may release IRQ assigned to PCI
interrupt. Later when pci_enable_device() is called during resume,
a different IRQ may be assigned and thus break the driver.
So keep IRQ assignment for PCI devices during suspend/hibernation.
We check pci_dev.dev.power.is_prepared to detect that pci_disable_device()
and pci_enable_device() is called during suspend/hibernation.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
Hi Borislav,
	I can't reproduce the issue with my test machine. So could you
please help to test this patch?
Regards!
Gerry
---
 arch/x86/pci/common.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 059a76c29739..417de4c92e8f 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -662,14 +662,15 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
 	if ((err = pci_enable_resources(dev, mask)) < 0)
 		return err;
 
-	if (!pci_dev_msi_enabled(dev))
+	if (!pci_dev_msi_enabled(dev) && !dev->dev.pm.is_prepared)
 		return pcibios_enable_irq(dev);
 	return 0;
 }
 
 void pcibios_disable_device (struct pci_dev *dev)
 {
-	if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
+	if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq &&
+	    !dev->dev.pm.is_prepared)
 		pcibios_disable_irq(dev);
 }
 
-- 
1.7.10.4