linux-kernel - [PATCH] PCI: qcom-ep: Do not enable resources during probe()

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Message-Id: <20240727090604.24646-1-manivannan.sadhasivam@linaro.org>
Date: Sat, 27 Jul 2024 14:36:04 +0530
From: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To: lpieralisi@...nel.org,
	kw@...ux.com
Cc: robh@...nel.org,
	bhelgaas@...gle.com,
	linux-arm-msm@...r.kernel.org,
	linux-pci@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Subject: [PATCH] PCI: qcom-ep: Do not enable resources during probe()

Starting from commit 869bc5253406 ("PCI: dwc: ep: Fix DBI access failure
for drivers requiring refclk from host"), all the hardware register access
(like DBI) were moved to dw_pcie_ep_init_registers() which gets called only
in qcom_pcie_perst_deassert() i.e., only after the endpoint received refclk
from host.

So there is no need to enable the endpoint resources (like clk, regulators,
PHY) during probe(). Hence, remove the call to qcom_pcie_enable_resources()
helper from probe(). This was added earlier because dw_pcie_ep_init() was
doing DBI access, which is not done now.

While at it, let's also call dw_pcie_ep_deinit() in err path to deinit the
EP controller in the case of failure.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
---
 drivers/pci/controller/dwc/pcie-qcom-ep.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 236229f66c80..2319ff2ae9f6 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -846,21 +846,15 @@ static int qcom_pcie_ep_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = qcom_pcie_enable_resources(pcie_ep);
-	if (ret) {
-		dev_err(dev, "Failed to enable resources: %d\n", ret);
-		return ret;
-	}
-
 	ret = dw_pcie_ep_init(&pcie_ep->pci.ep);
 	if (ret) {
 		dev_err(dev, "Failed to initialize endpoint: %d\n", ret);
-		goto err_disable_resources;
+		return ret;
 	}
 
 	ret = qcom_pcie_ep_enable_irq_resources(pdev, pcie_ep);
 	if (ret)
-		goto err_disable_resources;
+		goto err_ep_deinit;
 
 	name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
 	if (!name) {
@@ -877,8 +871,8 @@ static int qcom_pcie_ep_probe(struct platform_device *pdev)
 	disable_irq(pcie_ep->global_irq);
 	disable_irq(pcie_ep->perst_irq);
 
-err_disable_resources:
-	qcom_pcie_disable_resources(pcie_ep);
+err_ep_deinit:
+	dw_pcie_ep_deinit(&pcie_ep->pci.ep);
 
 	return ret;
 }
-- 
2.25.1