[PATCH v2] PCI: starfive: Enable PCIe controller's runtime PM before probing host bridge

[Mayank Rana]

PCIe controller device (i.e. PCIe starfive device) is parent to PCIe host
bridge device. To enable runtime PM of PCIe host bridge device (child
device), it is must to enable parent device's runtime PM to avoid seeing
WARN_ON as "Enabling runtime PM for inactive device with active children".
Fix this issue by enabling starfive pcie controller device's runtime PM
before calling into pci_host_probe() through plda_pcie_host_init().

Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Mayank Rana <quic_mrana@xxxxxxxxxxx>
---
v1->v2: Updated commit description based on Bjorn's feedback
Link to v1: https://patchwork.kernel.org/project/linux-pci/patch/20241010202950.3263899-1-quic_mrana@xxxxxxxxxxx/
 
 drivers/pci/controller/plda/pcie-starfive.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/plda/pcie-starfive.c b/drivers/pci/controller/plda/pcie-starfive.c
index 0567ec373a3e..e73c1b7bc8ef 100644
--- a/drivers/pci/controller/plda/pcie-starfive.c
+++ b/drivers/pci/controller/plda/pcie-starfive.c
@@ -404,6 +404,9 @@ static int starfive_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
 	plda->host_ops = &sf_host_ops;
 	plda->num_events = PLDA_MAX_EVENT_NUM;
 	/* mask doorbell event */
@@ -413,11 +416,12 @@ static int starfive_pcie_probe(struct platform_device *pdev)
 	plda->events_bitmap <<= PLDA_NUM_DMA_EVENTS;
 	ret = plda_pcie_host_init(&pcie->plda, &starfive_pcie_ops,
 				  &stf_pcie_event);
-	if (ret)
+	if (ret) {
+		pm_runtime_put_sync(&pdev->dev);
+		pm_runtime_disable(&pdev->dev);
 		return ret;
+	}
 
-	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
 	platform_set_drvdata(pdev, pcie);
 
 	return 0;
-- 
2.25.1