[PATCH 1/7] PCI: qcom: fix parsing of PERST# in the legacy case

[Dmitry Baryshkov]

Commit deed8aec62dc ("PCI: qcom: Handle mixed PERST#/PHY DT
configuration") fixed support for the "mixed" platforms which declare
PERST# pin the RC node and the PHY in the RP node, however it also broke
support for a majority of existing platforms, which declare both PERST#
and PHY in the RC node, because now PERST# is first acquired in
qcom_pcie_parse_ports(), which then returns -ENODEV (as there are no
PHYs in the RP nodes). Later qcom_pcie_parse_legacy_binding() tries to
acquire the PERST# GPIO again and fails with -EBUSY (as the GPIO has
already been requested).

Move parsing of RC's perst-gpios to qcom_pcie_probe(), making it obvious
that it's shared for both cases and skip parsing it in both functions.

Fixes: deed8aec62dc ("PCI: qcom: Handle mixed PERST#/PHY DT configuration")
Closes: https://lore.kernel.org/r/gieaybsg2ckxpctvqj77nlwu7utama2yeyvebkonmexsxrra3v@v3fobqasxnmy/
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at oss.qualcomm.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 11fc60489892..7664c7c28c0e 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1907,15 +1907,6 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
 	struct device *dev = pcie->pci->dev;
 	int ret = -ENODEV;
 
-	if (of_find_property(dev->of_node, "perst-gpios", NULL)) {
-		pcie->reset = devm_gpiod_get_optional(dev, "perst",
-						      GPIOD_OUT_HIGH);
-		if (IS_ERR(pcie->reset))
-			return PTR_ERR(pcie->reset);
-
-		dev_warn(dev, "Reusing PERST# from Root Complex node. DT needs to be fixed!\n");
-	}
-
 	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
 		if (!of_node_is_type(of_port, "pci"))
 			continue;
@@ -1942,7 +1933,6 @@ static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
 	struct device *dev = pcie->pci->dev;
 	struct qcom_pcie_perst *perst;
 	struct qcom_pcie_port *port;
-	struct gpio_desc *reset;
 	struct phy *phy;
 	int ret;
 
@@ -1950,10 +1940,6 @@ static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
 	if (IS_ERR(phy))
 		return PTR_ERR(phy);
 
-	reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
-	if (IS_ERR(reset))
-		return PTR_ERR(reset);
-
 	ret = phy_init(phy);
 	if (ret)
 		return ret;
@@ -1970,7 +1956,7 @@ static int qcom_pcie_parse_legacy_binding(struct qcom_pcie *pcie)
 	INIT_LIST_HEAD(&port->list);
 	list_add_tail(&port->list, &pcie->ports);
 
-	perst->desc = reset;
+	perst->desc = pcie->reset;
 	INIT_LIST_HEAD(&port->perst);
 	INIT_LIST_HEAD(&perst->list);
 	list_add_tail(&perst->list, &port->perst);
@@ -2107,6 +2093,15 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 
 	pp->ops = &qcom_pcie_dw_ops;
 
+	if (of_find_property(dev->of_node, "perst-gpios", NULL)) {
+		pcie->reset = devm_gpiod_get_optional(dev, "perst",
+						      GPIOD_OUT_HIGH);
+		if (IS_ERR(pcie->reset))
+			return PTR_ERR(pcie->reset);
+
+		dev_warn(dev, "Reusing PERST# from Root Complex node. DT needs to be updated!\n");
+	}
+
 	ret = qcom_pcie_parse_ports(pcie);
 	if (ret) {
 		if (ret != -ENODEV) {

-- 
2.47.3