[2/3] PCI: imx6: allow MSI irq to be absent

Commit Message

Lucas Stach Aug. 28, 2017, 2:23 p.m. UTC

The host can fall back to PCIe legacy IRQ only operation if the MSI irq is
missing, thus allowing systems to work with peripherals that don't support
MSI irqs.

Signed-off-by: Lucas Stach <[e-mail]>
---
 .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  8 ++++----
 drivers/pci/dwc/pci-imx6.c                         | 23 +++++++++++-----------
 2 files changed, 15 insertions(+), 16 deletions(-)

Patch

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index cf92d3ba5a26..d85db21503f4 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -10,14 +10,14 @@  Required properties:
 	- "fsl,imx6qp-pcie"
 	- "fsl,imx7d-pcie"
 - reg: base address and length of the PCIe controller
-- interrupts: A list of interrupt outputs of the controller. Must contain an
-  entry for each entry in the interrupt-names property.
-- interrupt-names: Must include the following entries:
-	- "msi": The interrupt that is asserted when an MSI is received
 - clock-names: Must include the following additional entries:
 	- "pcie_phy"
 
 Optional properties:
+- interrupts: A list of interrupt outputs of the controller. Must contain an
+  entry for each entry in the interrupt-names property.
+- interrupt-names: Must include the following entries:
+        - "msi": The interrupt that is asserted when an MSI is received
 - fsl,tx-deemph-gen1: Gen1 De-emphasis value. Default: 0
 - fsl,tx-deemph-gen2-3p5db: Gen2 (3.5db) De-emphasis value. Default: 0
 - fsl,tx-deemph-gen2-6db: Gen2 (6db) De-emphasis value. Default: 20
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index bf5c3616e344..d2507272b3ab 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -671,18 +671,17 @@  static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
 
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
-		if (pp->msi_irq <= 0) {
-			dev_err(dev, "failed to get MSI irq\n");
-			return -ENODEV;
-		}
-
-		ret = devm_request_irq(dev, pp->msi_irq,
-				       imx6_pcie_msi_handler,
-				       IRQF_SHARED | IRQF_NO_THREAD,
-				       "mx6-pcie-msi", imx6_pcie);
-		if (ret) {
-			dev_err(dev, "failed to request MSI irq\n");
-			return ret;
+		if (pp->msi_irq > 0) {
+			ret = devm_request_irq(dev, pp->msi_irq,
+					       imx6_pcie_msi_handler,
+					       IRQF_SHARED | IRQF_NO_THREAD,
+					       "mx6-pcie-msi", imx6_pcie);
+			if (ret) {
+				dev_err(dev, "failed to request MSI irq\n");
+				return ret;
+			}
+		} else {
+			dev_info(dev, "missing MSI irq, MSI support unavailable\n");
 		}
 	}