[PATCH v2 2/2] PCI: qcom: Implement shutdown() callback

[Krishna Chaitanya Chundru]

From: Manivannan Sadhasivam <mani@xxxxxxxxxx>

PCIe host controllers should bring the link down cleanly before system
shutdown/reboot proceeds to remove power/clocks from the controller.
Without this, the link may still be up and endpoints still have
transactions in flight when power/clocks are cut, which can trip SMMU
translation faults or NoC protocol errors.

Reuse dw_pcie_suspend_noirq() in the shutdown path to force the link
into L2, putting it into D3cold.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index d8eb52857f69..f6a0cbb6a49e 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -2156,6 +2156,15 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static void qcom_pcie_shutdown(struct platform_device *pdev)
+{
+	struct qcom_pcie *pcie = platform_get_drvdata(pdev);
+
+	dw_pcie_suspend_noirq(pcie->pci);
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+}
+
 static int qcom_pcie_suspend_noirq(struct device *dev)
 {
 	struct qcom_pcie *pcie;
@@ -2337,5 +2346,6 @@ static struct platform_driver qcom_pcie_driver = {
 		.pm = &qcom_pcie_pm_ops,
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
+	.shutdown = qcom_pcie_shutdown,
 };
 builtin_platform_driver(qcom_pcie_driver);

-- 
2.34.1