How to get PCIE GEN3 Signal with PCIE TEST Fixture

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
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1

HI Dear All,
We have custom carrier board for the nVIDIA Jetson Xavier Module
We need test PCIE GEN3 x1/x4/x8,When we connect the pcie test fixture, we can’t get any pcie signal,But if pcie slot is connected to Device such as ssd, wifi module etc, PCIE signal can be measured.
How can we enable PCIE Pattern with PCIE TEST Fixture?
Please experts for suggestions Thank you!
Ryan

3

Based on your observations, I think your “PCIE TEST Fixture” doesn’t behave like an endpoint. AGX Xavier would shut down the root port controllers if there are no endpoints detected. If you want to stop this and have root ports to get enumerated even with no endpoints connected (or with Test Fixture connected which is not an endpoint), then, please remove “nvidia,enable-power-down” from the device-tree nodes of respective controllers.

4

Dear Vidyas
Thank you for your information
But I don’t know how to remove “nvidia, enable-power-down”
Can you please be more specific, how to remove this?
Do you have any command for control to “nvidia enable-power”?

5

Please refer to the BSP documentation on how to change and update the device-tree.

6

HI Sir
Our team already rebuild code for to remove “nvidia, enable-power-down”
but we still can’t get PCIE Pattern in default
Can you help me check under code ?

Thank you sir

pcie@14180000 {
status = “okay”;

	vddio-pex-ctl-supply = <&p2888_spmic_sd3>;
	nvidia,disable-aspm-states = <0xf>;
	//nvidia,enable-power-down;
	nvidia,disable-clock-request;

	phys = <&p2u_2>,
	       <&p2u_3>,
	       <&p2u_4>,
	       <&p2u_5>;
	phy-names = "pcie-p2u-0", "pcie-p2u-1", "pcie-p2u-2", "pcie-p2u-3";
};

pcie@14100000 {
	status = "okay";

	vddio-pex-ctl-supply = <&p2888_spmic_sd3>;
	nvidia,disable-aspm-states = <0xc>;
	//nvidia,enable-power-down;
	nvidia,disable-clock-request;

	nvidia,max-speed = <2>;

	phys = <&p2u_0>;
	phy-names = "pcie-p2u-0";
};

pcie@14140000 {
	status = "okay";

	nvidia,pex-wake = <&tegra_main_gpio TEGRA194_MAIN_GPIO(L, 2)
				GPIO_ACTIVE_HIGH>;
	vddio-pex-ctl-supply = <&p2888_spmic_sd3>;
	nvidia,disable-aspm-states = <0xf>;
	//nvidia,enable-power-down;
	nvidia,disable-clock-request;

	phys = <&p2u_7>;
	phy-names = "pcie-p2u-0";
};
7

The slot which you are checking is owned by which controller?
I see that you have disabled the power down for C0, C1, and C3 controllers but not for C4 and C5 (i.e. 0x14160000 and 0x141a0000 respectively). In case you are checking it on C4/C5, then, it won’t work because it still has power down enabled.