Not able to move Jetson Nano into L1SS mode

We are trying to get Jetson Nano into L1SS mode.

I have made the below changes

• Enabled CONFIG_PCIEASPM and CONFIG_PCIEASPM_POWERSAVE in file : /Linux_for_Tegra/sources/kernel/kernel-4.9/arch/arm64/configs/tegra_deconfig


• Removed “nvidia,disable-clock-request;” from file : /Linux_for_Tegra/sources/hardware/nvidia/platform/t210/porg/kernel-dts/porg-platforms/tegra210-porg-pcie.dtsi

After building and flashing Image on Jetson Nano Board

I could still see “nvidia,disable-clock-request” under /proc/device-tree/pcie@1003000/pci@1,0

root@ifxhost:/proc/device-tree/pcie@1003000/pci@1,0# ls -al

total 0

drwxr-xr-x 2 root root 0 Jul 21 18:55 .

drwxr-xr-x 5 root root 0 Jul 21 18:55 …

-r–r–r-- 1 root root 4 Jul 21 18:56 ‘#address-cells’

-r–r–r-- 1 root root 20 Jul 21 18:56 assigned-addresses

-r–r–r-- 1 root root 4 Jul 21 18:56 device_type

-r–r–r-- 1 root root 4 Jul 21 18:56 name

-r–r–r-- 1 root root 4 Jul 21 18:56 nvidia,afi-ctl-offset

-r–r–r-- 1 root root 4 Jul 21 18:56 nvidia,disable-aspm-states

-r–r–r-- 1 root root 0 Jul 21 18:56 nvidia,disable-clock-request

-r–r–r-- 1 root root 4 Jul 21 18:56 nvidia,num-lanes

-r–r–r-- 1 root root 28 Jul 21 18:56 phy-names

-r–r–r-- 1 root root 16 Jul 21 18:56 phys

-r–r–r-- 1 root root 0 Jul 21 18:56 ranges

-r–r–r-- 1 root root 20 Jul 21 18:56 reg

-r–r–r-- 1 root root 4 Jul 21 18:56 ‘#size-cells’

-r–r–r-- 1 root root 5 Jul 21 18:56 status

lspci command output:

    Capabilities: [240 v1] L1 PM Substates

            L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+ L1_PM_Substates+

                      PortCommonModeRestoreTime=8us PortTPowerOnTime=50us

            L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-

                       T_CommonMode=0us LTR1.2_Threshold=0ns

            L1SubCtl2: T_PwrOn=50us

To cross check my changes on the Jetson Nano board

• Time stamp of dtb file(File: /boot/kernel_tegra210-p3448-0000-p3449-0000-b00.dtb) matches my build time.


• I have decompiled the dtb file(File: /boot/kernel_tegra210-p3448-0000-p3449-0000-b00.dtb) and generated the dts File.


• I did not see “nvidia,disable-clock-request” tag from the generated dts file.

Software Used: We are suing the 32.6.1 BSP Release Package.

Please let us know the changes required and process to get Jetson Nano into L1SS mode also process/command to know if the Nano configured to L1SS Mode properly