[PATCH v8 8/9] arm64: tegra: Add aspm-l1-entry-delay-ns to PCIe nodes

Manikanta Maddireddy
2026-03-24T19:11:45Z

Add the aspm-l1-entry-delay-ns device tree property to all PCIe Root Port
and PCIe Endpoint nodes in tegra194.dtsi and tegra234.dtsi so that ASPM L1
entrance latency is configured from device tree.

- Tegra194: 4000 ns (4 us) for both Root Port and Endpoint.
- Tegra234: 8000 ns (8 us) for Root Port, 16000 ns (16 us) for Endpoint.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
V8: New patch

arch/arm64/boot/dts/nvidia/tegra194.dtsi | 9 +++++++++
arch/arm64/boot/dts/nvidia/tegra234.dtsi | 16 ++++++++++++++++
2 files changed, 25 insertions(+)

diff --git a/arch/arm64/boot/dts/nvidia/tegra194.dtsi b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
index 849694f751d9..1d659454a6f9 100644
--- a/arch/arm64/boot/dts/nvidia/tegra194.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
@@ -2382,6 +2382,7 @@ pcie@14100000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

bus-range = <0x0 0xff>;

@@ -2434,6 +2435,7 @@ pcie@14120000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

bus-range = <0x0 0xff>;

@@ -2486,6 +2488,7 @@ pcie@14140000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

bus-range = <0x0 0xff>;

@@ -2538,6 +2541,7 @@ pcie@14160000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

bus-range = <0x0 0xff>;

@@ -2583,6 +2587,7 @@ pcie-ep@14160000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

interconnects = <&mc TEGRA194_MEMORY_CLIENT_PCIE4R &emc>,
<&mc TEGRA194_MEMORY_CLIENT_PCIE4W &emc>;
@@ -2629,6 +2634,7 @@ pcie@14180000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

bus-range = <0x0 0xff>;

@@ -2674,6 +2680,7 @@ pcie-ep@14180000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

interconnects = <&mc TEGRA194_MEMORY_CLIENT_PCIE0R &emc>,
<&mc TEGRA194_MEMORY_CLIENT_PCIE0W &emc>;
@@ -2723,6 +2730,7 @@ pcie@141a0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

bus-range = <0x0 0xff>;

@@ -2771,6 +2779,7 @@ pcie-ep@141a0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <4000>;

interconnects = <&mc TEGRA194_MEMORY_CLIENT_PCIE5R &emc>,
<&mc TEGRA194_MEMORY_CLIENT_PCIE5W &emc>;
diff --git a/arch/arm64/boot/dts/nvidia/tegra234.dtsi b/arch/arm64/boot/dts/nvidia/tegra234.dtsi
index 850c473235e3..850c1a645d71 100644
--- a/arch/arm64/boot/dts/nvidia/tegra234.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra234.dtsi
@@ -4532,6 +4532,7 @@ pcie@140a0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4586,6 +4587,7 @@ pcie@140c0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4640,6 +4642,7 @@ pcie@140e0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4686,6 +4689,7 @@ pcie-ep@140e0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <16000>;

interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE10AR &emc>,
<&mc TEGRA234_MEMORY_CLIENT_PCIE10AW &emc>;
@@ -4734,6 +4738,7 @@ pcie@14100000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4788,6 +4793,7 @@ pcie@14120000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4842,6 +4848,7 @@ pcie@14140000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4896,6 +4903,7 @@ pcie@14160000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -4937,6 +4945,7 @@ pcie-ep@14160000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <16000>;

interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE4R &emc>,
<&mc TEGRA234_MEMORY_CLIENT_PCIE4W &emc>;
@@ -4983,6 +4992,7 @@ pcie@14180000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -5037,6 +5047,7 @@ pcie@141a0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -5083,6 +5094,7 @@ pcie-ep@141a0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <16000>;

interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE5R &emc>,
<&mc TEGRA234_MEMORY_CLIENT_PCIE5W &emc>;
@@ -5131,6 +5143,7 @@ pcie@141c0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -5177,6 +5190,7 @@ pcie-ep@141c0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <16000>;

interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE6AR &emc>,
<&mc TEGRA234_MEMORY_CLIENT_PCIE6AW &emc>;
@@ -5225,6 +5239,7 @@ pcie@141e0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <8000>;

bus-range = <0x0 0xff>;

@@ -5271,6 +5286,7 @@ pcie-ep@141e0000 {
nvidia,aspm-cmrt-us = <60>;
nvidia,aspm-pwr-on-t-us = <20>;
nvidia,aspm-l0s-entrance-latency-us = <3>;
+ aspm-l1-entry-delay-ns = <16000>;

interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE7AR &emc>,
<&mc TEGRA234_MEMORY_CLIENT_PCIE7AW &emc>;
--
2.34.1