In the kernel tree, try grepping for perst-gpio:
$ grep -r 'perst-gpio' .
./Documentation/devicetree/bindings/pci/qcom,pcie.txt: - "perst-gpios" PCIe endpoint reset signal line
./Documentation/devicetree/bindings/pci/qcom,pcie.txt: perst-gpio = <&tlmm 70 GPIO_ACTIVE_LOW>;
...
./arch/arm64/boot/dts/qcom/msm8998.dtsi: perst-gpios = <&tlmm 35 GPIO_ACTIVE_LOW>;
...
./arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi: perst-gpio = <&msmgpio 35 GPIO_ACTIVE_LOW>;
So which is it, “perst-gpios” or “perst-gpio”? My vote is for the plural, given the bindings documentation.
Fortunately, the property does not seem to be used anywhere in the code.
In ./arch/arm64/boot/dts/qcom/msm8998.dtsi:
/ {soc: soc {
agnoc@0 {
pcie2: pcie@610000 {
ranges = <0x01000000 0x0 0x0e200000 0x0e200000 0x0 0x100000>,
<0x02000000 0x0 0x0e300000 0x0e300000 0x0 0x1d00000>;
Should the memory range size be 0x1d00000 or should it be 0xd00000 like the two other root complexes?