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From:   Jianjun Wang <jianjun.wang@mediatek.com>
To:     Lorenzo Pieralisi <lpieralisi@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Marc Zyngier <maz@kernel.org>
CC:     Ryder Lee <ryder.lee@mediatek.com>,
        Jianjun Wang <jianjun.wang@mediatek.com>,
        <linux-pci@vger.kernel.org>, <linux-mediatek@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <jieyy.yang@mediatek.com>,
        <chuanjia.liu@mediatek.com>, <qizhong.cheng@mediatek.com>,
        <jian.yang@mediatek.com>, <jianguo.zhang@mediatek.com>
Subject: [PATCH v2 2/3] PCI: mediatek-gen3: Do not break probe flow when MSI init fails
Date:   Mon, 11 Dec 2023 16:52:55 +0800
Message-ID: <20231211085256.31292-3-jianjun.wang@mediatek.com>
In-Reply-To: <20231211085256.31292-1-jianjun.wang@mediatek.com>
References: <20231211085256.31292-1-jianjun.wang@mediatek.com>
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Since INTx can still work, the driver probe flow should not be broken by
MSI initialization failures. Additionally, moving the MSI initialization
code into a single function enhances readability.

Fixes: 1bdafba538be ("PCI: mediatek-gen3: Add MSI support")
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
---
 drivers/pci/controller/pcie-mediatek-gen3.c | 68 ++++++++++-----------
 1 file changed, 33 insertions(+), 35 deletions(-)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index c1ae3d19ec9a..c6a6876d233a 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -649,59 +649,51 @@ static const struct irq_domain_ops intx_domain_ops = {
 	.map = mtk_pcie_intx_map,
 };
 
-static int mtk_pcie_init_irq_domains(struct mtk_gen3_pcie *pcie)
+static int mtk_pcie_init_msi(struct mtk_gen3_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
-	struct device_node *intc_node, *node = dev->of_node;
-	int ret;
-
-	raw_spin_lock_init(&pcie->irq_lock);
-
-	/* Setup INTx */
-	intc_node = of_get_child_by_name(node, "interrupt-controller");
-	if (!intc_node) {
-		dev_err(dev, "missing interrupt-controller node\n");
-		return -ENODEV;
-	}
-
-	pcie->intx_domain = irq_domain_add_linear(intc_node, PCI_NUM_INTX,
-						  &intx_domain_ops, pcie);
-	if (!pcie->intx_domain) {
-		dev_err(dev, "failed to create INTx IRQ domain\n");
-		ret = -ENODEV;
-		goto out_put_node;
-	}
+	struct device_node *node = dev->of_node;
 
-	/* Setup MSI */
 	mutex_init(&pcie->lock);
 
 	pcie->msi_bottom_domain = irq_domain_add_linear(node, PCIE_MSI_IRQS_NUM,
 				  &mtk_msi_bottom_domain_ops, pcie);
 	if (!pcie->msi_bottom_domain) {
 		dev_err(dev, "failed to create MSI bottom domain\n");
-		ret = -ENODEV;
-		goto err_msi_bottom_domain;
+		return -ENODEV;
 	}
 
-	pcie->msi_domain = pci_msi_create_irq_domain(dev->fwnode,
-						     &mtk_msi_domain_info,
+	pcie->msi_domain = pci_msi_create_irq_domain(dev->fwnode, &mtk_msi_domain_info,
 						     pcie->msi_bottom_domain);
 	if (!pcie->msi_domain) {
 		dev_err(dev, "failed to create MSI domain\n");
-		ret = -ENODEV;
-		goto err_msi_domain;
+		irq_domain_remove(pcie->msi_bottom_domain);
+		return -ENODEV;
 	}
 
-	of_node_put(intc_node);
 	return 0;
+}
 
-err_msi_domain:
-	irq_domain_remove(pcie->msi_bottom_domain);
-err_msi_bottom_domain:
-	irq_domain_remove(pcie->intx_domain);
-out_put_node:
+static int mtk_pcie_init_intx(struct mtk_gen3_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct device_node *intc_node, *node = dev->of_node;
+
+	intc_node = of_get_child_by_name(node, "interrupt-controller");
+	if (!intc_node) {
+		dev_err(dev, "missing interrupt-controller node\n");
+		return -ENODEV;
+	}
+
+	pcie->intx_domain = irq_domain_add_linear(intc_node, PCI_NUM_INTX,
+						  &intx_domain_ops, pcie);
 	of_node_put(intc_node);
-	return ret;
+	if (!pcie->intx_domain) {
+		dev_err(dev, "failed to create INTx IRQ domain\n");
+		return -ENODEV;
+	}
+
+	return 0;
 }
 
 static void mtk_pcie_irq_teardown(struct mtk_gen3_pcie *pcie)
@@ -774,10 +766,16 @@ static int mtk_pcie_setup_irq(struct mtk_gen3_pcie *pcie)
 	struct platform_device *pdev = to_platform_device(dev);
 	int err;
 
-	err = mtk_pcie_init_irq_domains(pcie);
+	raw_spin_lock_init(&pcie->irq_lock);
+
+	err = mtk_pcie_init_intx(pcie);
 	if (err)
 		return err;
 
+	err = mtk_pcie_init_msi(pcie);
+	if (err)
+		dev_warn(dev, "no MSI supported, only INTx available\n");
+
 	pcie->irq = platform_get_irq(pdev, 0);
 	if (pcie->irq < 0)
 		return pcie->irq;
-- 
2.18.0