[Patch v2 4/4] PCI, MSI: Optionally free legacy PCI IRQ when enabling MSI/MSI-X

Jiang Liu
2015-06-02T02:48:07Z

Once PCI MSI/MSI-X is enabled by the device driver, PCI device won't
make use of legacy PCI IRQ until PCI MSI/MSI-X is disabled again.
So optionally free legacy PCI IRQ when enabling MSI/MSI-X and reallocate
when disabling MSI/MSI-X.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/pci/msi.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index c3e7dfcf9ff5..47cf72c669f0 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -686,6 +686,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
msi_set_enable(dev, 1);
dev->msi_enabled = 1;

+ pcibios_free_irq(dev);
dev->irq = entry->irq;
return 0;
}
@@ -813,9 +814,10 @@ static int msix_capability_init(struct pci_dev *dev,
/* Set MSI-X enabled bits and unmask the function */
pci_intx_for_msi(dev, 0);
dev->msix_enabled = 1;
-
msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);

+ pcibios_free_irq(dev);
+
return 0;

out_avail:
@@ -930,6 +932,7 @@ void pci_msi_shutdown(struct pci_dev *dev)

/* Restore dev->irq to its default pin-assertion irq */
dev->irq = desc->msi_attrib.default_irq;
+ pcibios_alloc_irq(dev);
}

void pci_disable_msi(struct pci_dev *dev)
@@ -1030,6 +1033,7 @@ void pci_msix_shutdown(struct pci_dev *dev)
msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
pci_intx_for_msi(dev, 1);
dev->msix_enabled = 0;
+ pcibios_alloc_irq(dev);
}

void pci_disable_msix(struct pci_dev *dev)
--
1.7.10.4