PCI: qcom: Skip PERST# GPIOs provided by downstream PCIe devices

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Currently, the pcie-qcom driver recursively parses the PERST# GPIO from all
child nodes defined in DT and acquires them. But this creates issues with
PERST# GPIO provided by one of the child devices like the PCIe switch port.
In this case, the RC driver cannot acquire the PERST# GPIO since it will be
provided by the child PCIe device which was not yet enumerated during RC
driver probe.

Fix this by checking if the GPIO provider is a child of the RC's DT node
(i.e., sits behind this PCIe controller). If so, skip it, as PERST#
should be controlled by the respective PCIe client driver implementation.
GPIOs provided by external GPIO controllers (e.g., TLMM in Qcom SoCs)
continue to be handled normally.

Fixes: 2fd60a2edb ("PCI: qcom: Parse PERST# from all PCIe bridge nodes")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20260616-pci-qcom-perst-fix-v1-1-27600d6ae357@oss.qualcomm.com

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Manivannan Sadhasivam 2026-06-16 21:45:19 +05:30 • committed by Manivannan Sadhasivam

parent 5331711738

commit 3edb3a038d

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drivers/pci/controller/dwc/pcie-qcom.c

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