Re: [PATCH] PCI: qcom: avoid duplicate PERST# GPIO acquisition in legacy path

[Manivannan Sadhasivam]

On Tue, May 26, 2026 at 05:02:30PM +0530, Kathiravan Thirumoorthy wrote:
> Commit deed8aec62dc ("PCI: qcom: Handle mixed PERST#/PHY DT
> configuration") handles the case where the PHY is moved to the Root
> Port node while PERST# remains in the RC node by acquiring the PERST#
> GPIO during Root Port parsing.
> 
> However, on platforms such as IPQ5424, both PERST# and PHY are
> described under the RC node and are intended to be handled via the
> legacy binding path. Since PERST# is already acquired during Root Port
> parsing, attempting to acquire it again in the legacy path fails,
> resulting in probe failures as shown below:
> 
> [    1.571859] qcom-pcie 18000000.pcie: probe with driver qcom-pcie failed with error -16
> [    1.571909] qcom-pcie 10000000.pcie: probe with driver qcom-pcie failed with error -16
> [    1.571973] qcom-pcie 20000000.pcie: probe with driver qcom-pcie failed with error -16
> 
> Fix this by removing the redundant GPIO acquisition from
> qcom_pcie_parse_legacy_binding() and reusing the PERST# descriptor
> obtained in qcom_pcie_parse_ports().
> 
> While at it, move the warning message to qcom_pcie_parse_perst() to
> avoid polluting dmesg when the legacy binding is used.
> 
> Fixes: deed8aec62dc ("PCI: qcom: Handle mixed PERST#/PHY DT configuration")
> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 11fc60489892..77cbd204ac5c 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -1824,6 +1824,7 @@ static int qcom_pcie_parse_perst(struct qcom_pcie *pcie,
>  	int ret;
>  
>  	if (pcie->reset) {
> +		dev_warn(dev, "Reusing PERST# from Root Complex node. DT needs to be fixed!\n");

This will cause spat for each child node. So switched to dev_warn_once() and
squashed this fix to the offending commit, thanks!

- Mani

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