[PATCH] iommu/rockchip: Don't loop until failure to count interrupts

[Enric Balletbo i Serra]

As platform_get_irq() now prints an error when the interrupt does not
exist, counting interrupts by looping until failure causes the printing
of scary messages like:

 rk_iommu ff924000.iommu: IRQ index 1 not found
 rk_iommu ff914000.iommu: IRQ index 1 not found
 rk_iommu ff903f00.iommu: IRQ index 1 not found
 rk_iommu ff8f3f00.iommu: IRQ index 1 not found
 rk_iommu ff650800.iommu: IRQ index 1 not found

Fix this by using the platform_irq_count() helper to avoid touching
non-existent interrupts.

Fixes: 7723f4c5ecdb8d83 ("driver core: platform: Add an error message to platform_get_irq*()")
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---

 drivers/iommu/rockchip-iommu.c | 35 +++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 26290f310f90..8c6318bd1b37 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -1136,7 +1136,7 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	struct rk_iommu *iommu;
 	struct resource *res;
 	int num_res = pdev->num_resources;
-	int err, i, irq;
+	int err, i, irq, num_irqs;
 
 	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
 	if (!iommu)
@@ -1219,20 +1219,28 @@ static int rk_iommu_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(dev);
 
-	i = 0;
-	while ((irq = platform_get_irq(pdev, i++)) != -ENXIO) {
-		if (irq < 0)
-			return irq;
+	num_irqs = platform_irq_count(pdev);
+	if (num_irqs < 0) {
+		err = num_irqs;
+		goto err_disable_pm_runtime;
+	}
+
+	for (i = 0; i < num_irqs; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0) {
+			err = irq;
+			goto err_disable_pm_runtime;
+		}
 
 		err = devm_request_irq(iommu->dev, irq, rk_iommu_irq,
 				       IRQF_SHARED, dev_name(dev), iommu);
-		if (err) {
-			pm_runtime_disable(dev);
-			goto err_remove_sysfs;
-		}
+		if (err)
+			goto err_disable_pm_runtime;
 	}
 
 	return 0;
+err_disable_pm_runtime:
+	pm_runtime_disable(dev);
 err_remove_sysfs:
 	iommu_device_sysfs_remove(&iommu->iommu);
 err_put_group:
@@ -1245,10 +1253,15 @@ static int rk_iommu_probe(struct platform_device *pdev)
 static void rk_iommu_shutdown(struct platform_device *pdev)
 {
 	struct rk_iommu *iommu = platform_get_drvdata(pdev);
-	int i = 0, irq;
+	int i, irq, num_irqs;
 
-	while ((irq = platform_get_irq(pdev, i++)) != -ENXIO)
+	num_irqs = platform_irq_count(pdev);
+	for (i = 0; i < num_irqs; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0)
+			continue;
 		devm_free_irq(iommu->dev, irq, iommu);
+	}
 
 	pm_runtime_force_suspend(&pdev->dev);
 }
-- 
2.20.1