[PATCH 2/2] can: kvaser_pciefd: Add MSI interrupts

[Martin Jocic <martin.jocic@kvaser.com>]

Use MSI interrupts with fallback to legacy interrupts.

Signed-off-by: Martin Jocic <martin.jocic@kvaser.com>
---
 drivers/net/can/kvaser_pciefd.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index 63b4d2a4c7ce..53b82e11f7f3 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -1774,11 +1774,24 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev,
 	if (ret)
 		goto err_teardown_can_ctrls;

-	ret = request_irq(pcie->pci->irq, kvaser_pciefd_irq_handler,
-			  IRQF_SHARED, KVASER_PCIEFD_DRV_NAME, pcie);
-	if (ret)
+	ret = pci_alloc_irq_vectors(pcie->pci, 1, 1, PCI_IRQ_LEGACY | PCI_IRQ_MSI);
+	if (ret < 0) {
+		dev_info(&pcie->pci->dev, "Failed to allocate IRQ vectors.\n");
 		goto err_teardown_can_ctrls;
+	}
+
+	ret = pci_irq_vector(pcie->pci, 0);
+	if (ret < 0)
+		goto err_free_msi;
+
+	pcie->pci->irq = ret;

+	ret = request_irq(pcie->pci->irq, kvaser_pciefd_irq_handler,
+			  IRQF_SHARED, KVASER_PCIEFD_DRV_NAME, pcie);
+	if (ret) {
+		dev_info(&pcie->pci->dev, "Failed to request IRQ %d\n", pcie->pci->irq);
+		goto err_free_msi;
+	}
 	iowrite32(KVASER_PCIEFD_SRB_IRQ_DPD0 | KVASER_PCIEFD_SRB_IRQ_DPD1,
 		  KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_IRQ_REG);

@@ -1807,6 +1820,10 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev,
 	iowrite32(0, irq_en_base);
 	free_irq(pcie->pci->irq, pcie);

+err_free_msi:
+	if (pcie->pci->msi_enabled)
+		pci_free_irq_vectors(pcie->pci);
+
 err_teardown_can_ctrls:
 	kvaser_pciefd_teardown_can_ctrls(pcie);
 	iowrite32(0, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_CTRL_REG);
--
2.40.1