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From:   Peter Geis <pgwipeout@gmail.com>
To:     linux-rockchip@lists.infradead.org,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Heiko Stuebner <heiko@sntech.de>,
        Philipp Zabel <p.zabel@pengutronix.de>
Cc:     Peter Geis <pgwipeout@gmail.com>, Marc Zyngier <maz@kernel.org>,
        linux-pci@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Subject: [PATCH v9 2/5] PCI: rockchip-dwc: Reset core at driver probe
Date:   Fri, 29 Apr 2022 08:38:28 -0400
Message-Id: <20220429123832.2376381-3-pgwipeout@gmail.com>
In-Reply-To: <20220429123832.2376381-1-pgwipeout@gmail.com>
References: <20220429123832.2376381-1-pgwipeout@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The PCIe controller is in an unknown state at driver probe. This can
lead to undesireable effects when the driver attempts to configure the
controller.

Prevent issues in the future by resetting the core during probe.

Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 23 ++++++++-----------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index c9b341e55cbb..faedbd6ebc20 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -152,6 +152,11 @@ static int rockchip_pcie_resource_get(struct platform_device *pdev,
 	if (IS_ERR(rockchip->rst_gpio))
 		return PTR_ERR(rockchip->rst_gpio);
 
+	rockchip->rst = devm_reset_control_array_get_exclusive(&pdev->dev);
+	if (IS_ERR(rockchip->rst))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rockchip->rst),
+				     "failed to get reset lines\n");
+
 	return 0;
 }
 
@@ -182,18 +187,6 @@ static void rockchip_pcie_phy_deinit(struct rockchip_pcie *rockchip)
 	phy_power_off(rockchip->phy);
 }
 
-static int rockchip_pcie_reset_control_release(struct rockchip_pcie *rockchip)
-{
-	struct device *dev = rockchip->pci.dev;
-
-	rockchip->rst = devm_reset_control_array_get_exclusive(dev);
-	if (IS_ERR(rockchip->rst))
-		return dev_err_probe(dev, PTR_ERR(rockchip->rst),
-				     "failed to get reset lines\n");
-
-	return reset_control_deassert(rockchip->rst);
-}
-
 static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = rockchip_pcie_link_up,
 	.start_link = rockchip_pcie_start_link,
@@ -222,6 +215,10 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = reset_control_assert(rockchip->rst);
+	if (ret)
+		return ret;
+
 	/* DON'T MOVE ME: must be enable before PHY init */
 	rockchip->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
 	if (IS_ERR(rockchip->vpcie3v3)) {
@@ -241,7 +238,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		goto disable_regulator;
 
-	ret = rockchip_pcie_reset_control_release(rockchip);
+	ret = reset_control_deassert(rockchip->rst);
 	if (ret)
 		goto deinit_phy;
 
-- 
2.25.1