[BACKPORT 4.14.y 02/18] PCI: dra7xx: Fix legacy INTD IRQ handling

[Mathieu Poirier <mathieu.poirier@linaro.org>]

From: Vignesh R <vigneshr@ti.com>

commit 524d59f6e30aab5b618da55e604c802ccd83e708 upstream

Legacy INTD IRQ handling is broken on dra7xx due to fact that driver
uses hwirq in range of 1-4 for INTA, INTD whereas IRQ domain is of size
4 which is numbered 0-3. Therefore when INTD IRQ line is used with
pci-dra7xx driver following warning is seen:

       WARNING: CPU: 0 PID: 1 at kernel/irq/irqdomain.c:342 irq_domain_associate+0x12c/0x1c4
       error: hwirq 0x4 is too large for dummy

Fix this by using pci_irqd_intx_xlate() helper to translate the INTx 1-4
range into the 0-3 as done in other PCIe drivers.

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Reported-by: Chris Welch <Chris.Welch@viavisolutions.com>
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/pci/dwc/pci-dra7xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 63052c5e5f82..7f5dfa169d0f 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -227,6 +227,7 @@ static int dra7xx_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
 
 static const struct irq_domain_ops intx_domain_ops = {
 	.map = dra7xx_pcie_intx_map,
+	.xlate = pci_irqd_intx_xlate,
 };
 
 static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
@@ -270,7 +271,7 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
 	case INTC:
 	case INTD:
 		generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
-						    ffs(reg)));
+						    ffs(reg) - 1));
 		break;
 	}
 
-- 
2.17.1