[PATCH v2 1/7] PCI: qcom: fix parsing of PERST# in the legacy case

[Manivannan Sadhasivam]

On Mon, Jun 08, 2026 at 09:59:19AM +0300, Dmitry Baryshkov wrote:
> 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>

This issue is fixed now. You can drop this patch in next revision.

- Mani

> ---
>  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
> 

-- 
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