irqchip: armada-370-xp: implement the ->check_device() msi_chip operation

commit 830cbe4b upstream.

Until now, we were leaving the ->check_device() msi_chip operation
empty, which leads the PCI core to believe that we support both MSI
and MSI-X. In fact, we do not support MSI-X, so we have to tell this
to the PCI core by providing an implementation of this operation.

Fixes: 31f614ed ('irqchip: armada-370-xp: implement MSI support')
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397823593-1932-3-git-send-email-thomas.petazzoni@free-electrons.comTested-by: Neil Greatorex <neil@fatboyfat.co.uk>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/irqchip/irq-armada-370-xp.c

@@ -162,6 +162,15 @@ static void armada_370_xp_teardown_msi_irq(struct msi_chip *chip,
 	armada_370_xp_free_msi(d->hwirq);
 }
 
+static int armada_370_xp_check_msi_device(struct msi_chip *chip, struct pci_dev *dev,
+					  int nvec, int type)
+{
+	/* We support MSI, but not MSI-X */
+	if (type == PCI_CAP_ID_MSI)
+		return 0;
+	return -EINVAL;
+}
+
 static struct irq_chip armada_370_xp_msi_irq_chip = {
 	.name = "armada_370_xp_msi_irq",
 	.irq_enable = unmask_msi_irq,
@@ -200,6 +209,7 @@ static int armada_370_xp_msi_init(struct device_node *node,
 
 	msi_chip->setup_irq = armada_370_xp_setup_msi_irq;
 	msi_chip->teardown_irq = armada_370_xp_teardown_msi_irq;
+	msi_chip->check_device = armada_370_xp_check_msi_device;
 	msi_chip->of_node = node;
 
 	armada_370_xp_msi_domain =