Hello, > The remapped PCIe Root Port and the child device have PCI PM L1 substates > capability, but they are disabled originally. > > Here is a failed example on ASUS B1400CEAE: > > Capabilities: [900 v1] L1 PM Substates > L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1- ASPM_L1.2+ ASPM_L1.1- L1_PM_Substates+ > PortCommonModeRestoreTime=32us PortTPowerOnTime=10us > L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2+ ASPM_L1.1- > T_CommonMode=0us LTR1.2_Threshold=101376ns > L1SubCtl2: T_PwrOn=50us > > Power on all of the VMD remapped PCI devices to D0 before enable PCI-PM L1 > PM Substates by following "PCIe r6.0, sec 5.5.4". Applied to controller/vmd, thank you! [01/01] PCI: vmd: Set PCI devices to D0 before enable PCI PM's L1 substates https://git.kernel.org/pci/pci/c/c8d39213cb70 Krzysztof