Linux PCI subsystem development
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From: Manikanta Maddireddy <mmaddireddy@nvidia.com>
To: <bhelgaas@google.com>, <lpieralisi@kernel.org>,
	<kwilczynski@kernel.org>, <mani@kernel.org>, <robh@kernel.org>,
	<krzk+dt@kernel.org>, <conor+dt@kernel.org>,
	<thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
	<kishon@kernel.org>, <arnd@arndb.de>,
	<gregkh@linuxfoundation.org>, <Frank.Li@nxp.com>,
	<den@valinux.co.jp>, <hongxing.zhu@nxp.com>,
	<jingoohan1@gmail.com>, <vidyas@nvidia.com>, <cassel@kernel.org>,
	<18255117159@163.com>
Cc: <linux-pci@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	Manikanta Maddireddy <mmaddireddy@nvidia.com>
Subject: [PATCH v3 2/2] arm64: tegra: fix aspm-l1-entry-delay-ns L1 latency cells
Date: Fri, 15 May 2026 12:37:53 +0530	[thread overview]
Message-ID: <20260515070753.3852840-3-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20260515070753.3852840-1-mmaddireddy@nvidia.com>

The Tegra194 PCIe driver converts aspm-l1-entry-delay-ns to whole ms
with ceiling division, then derives the Synopsys DesignWare PORT_AFR L1
entrance latency encoding as min(order_base_2(us), 7).

The nanosecond values from the Fixes tag below round up to 4, 8, and 16 us,
selecting PORT_AFR L1 entrance latency codes 2, 3, and 4 respectively.
Raise the programmed latency so the PORT_AFR codes are 3 / 4 / 5
(8 / 16 / 32 us buckets) instead of 2 / 3 / 4 (4 / 8 / 16 us).

- tegra194.dtsi: 4000 -> 8000 ns (all listed controllers)
- tegra234.dtsi: 8000 -> 16000 ns (Root Port), 16000 -> 32000 ns (Endpoint)

Fixes: d60ed99f1c9e ("arm64: tegra: Add aspm-l1-entry-delay-ns to PCIe nodes")
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
 arch/arm64/boot/dts/nvidia/tegra194.dtsi | 18 ++++++-------
 arch/arm64/boot/dts/nvidia/tegra234.dtsi | 32 ++++++++++++------------
 2 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/arch/arm64/boot/dts/nvidia/tegra194.dtsi b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
index 1d659454a6f9..7bbf0e892724 100644
--- a/arch/arm64/boot/dts/nvidia/tegra194.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
@@ -2382,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -2435,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -2488,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -2541,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -2587,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			interconnects = <&mc TEGRA194_MEMORY_CLIENT_PCIE4R &emc>,
 					<&mc TEGRA194_MEMORY_CLIENT_PCIE4W &emc>;
@@ -2634,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -2680,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			interconnects = <&mc TEGRA194_MEMORY_CLIENT_PCIE0R &emc>,
 					<&mc TEGRA194_MEMORY_CLIENT_PCIE0W &emc>;
@@ -2730,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -2779,7 +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>;
+			aspm-l1-entry-delay-ns = <8000>;
 
 			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 75bb9a0ad027..8e0c51e496e2 100644
--- a/arch/arm64/boot/dts/nvidia/tegra234.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra234.dtsi
@@ -4532,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4587,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4642,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4689,7 +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>;
+			aspm-l1-entry-delay-ns = <32000>;
 
 			interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE10AR &emc>,
 					<&mc TEGRA234_MEMORY_CLIENT_PCIE10AW &emc>;
@@ -4738,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4793,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4848,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4903,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -4945,7 +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>;
+			aspm-l1-entry-delay-ns = <32000>;
 
 			interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE4R &emc>,
 				      <&mc TEGRA234_MEMORY_CLIENT_PCIE4W &emc>;
@@ -4992,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -5047,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -5094,7 +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>;
+			aspm-l1-entry-delay-ns = <32000>;
 
 			interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE5R &emc>,
 					<&mc TEGRA234_MEMORY_CLIENT_PCIE5W &emc>;
@@ -5143,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -5190,7 +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>;
+			aspm-l1-entry-delay-ns = <32000>;
 
 			interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE6AR &emc>,
 					<&mc TEGRA234_MEMORY_CLIENT_PCIE6AW &emc>;
@@ -5239,7 +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>;
+			aspm-l1-entry-delay-ns = <16000>;
 
 			bus-range = <0x0 0xff>;
 
@@ -5286,7 +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>;
+			aspm-l1-entry-delay-ns = <32000>;
 
 			interconnects = <&mc TEGRA234_MEMORY_CLIENT_PCIE7AR &emc>,
 					<&mc TEGRA234_MEMORY_CLIENT_PCIE7AW &emc>;
-- 
2.34.1


  parent reply	other threads:[~2026-05-15  7:09 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-15  7:07 [PATCH v3 0/2] PCI: tegra194: ASPM L1 entrance latency from device tree Manikanta Maddireddy
2026-05-15  7:07 ` [PATCH v3 1/2] PCI: tegra194: Use aspm-l1-entry-delay-ns DT property for L1 entrance latency Manikanta Maddireddy
2026-05-15  7:07 ` Manikanta Maddireddy [this message]
2026-05-15  7:45   ` [PATCH v3 2/2] arm64: tegra: fix aspm-l1-entry-delay-ns L1 latency cells sashiko-bot
2026-05-15  8:38     ` Manikanta Maddireddy

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