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Then, PCI PM's L1 substates control are initialized & enabled accordingly. Also, update the comments of pci_enable_link_state() and pci_enable_link_state_locked() for kernel-doc, too. Link: https://bugzilla.kernel.org/show_bug.cgi?id=218394 Signed-off-by: Jian-Hong Pan --- v2: - Power on the VMD remapped devices with pci_set_power_state_locked() - Prepare the PCIe LTR parameters before enable L1 Substates - Add note into the comments of both pci_enable_link_state() and pci_enable_link_state_locked() for kernel-doc. - The original patch set can be split as individual patches. drivers/pci/controller/vmd.c | 15 ++++++++++----- drivers/pci/pcie/aspm.c | 10 ++++++++++ 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 87b7856f375a..66e47a0dbf1a 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -751,11 +751,9 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) if (!(features & VMD_FEAT_BIOS_PM_QUIRK)) return 0; - pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); if (!pos) - return 0; + goto out_enable_link_state; /* * Skip if the max snoop LTR is non-zero, indicating BIOS has set it @@ -763,7 +761,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) */ pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, <r_reg); if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK))) - return 0; + goto out_enable_link_state; /* * Set the default values to the maximum required by the platform to @@ -775,6 +773,14 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg); pci_info(pdev, "VMD: Default LTR value set by driver\n"); +out_enable_link_state: + /* + * Make PCI devices at D0 when enable PCI-PM L1 PM Substates from + * Section 5.5.4 of PCIe Base Spec Revision 6.0 + */ + pci_set_power_state_locked(pdev, PCI_D0); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); + return 0; } @@ -926,7 +932,6 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) dev_get_msi_domain(&vmd->dev->dev)); vmd_acpi_begin(); - pci_scan_child_bus(vmd->bus); vmd_domain_reset(vmd); diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index bc0bd86695ec..5f902c5552ca 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1164,6 +1164,8 @@ static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked) link->aspm_default |= ASPM_STATE_L1_1_PCIPM | ASPM_STATE_L1; if (state & PCIE_LINK_STATE_L1_2_PCIPM) link->aspm_default |= ASPM_STATE_L1_2_PCIPM | ASPM_STATE_L1; + if (state & ASPM_STATE_L1_2_MASK) + aspm_l1ss_init(link); pcie_config_aspm_link(link, policy_to_aspm_state(link)); link->clkpm_default = (state & PCIE_LINK_STATE_CLKPM) ? 1 : 0; @@ -1182,6 +1184,10 @@ static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked) * touch the LNKCTL register. Also note that this does not enable states * disabled by pci_disable_link_state(). Return 0 or a negative errno. * + * Note: The PCIe devices of the link must be in D0, if the PCI-PM L1 PM + * substates are going to be enabled. From Section 5.5.4 of PCIe Base Spec + * Revision 6.0. + * * @pdev: PCI device * @state: Mask of ASPM link states to enable */ @@ -1198,6 +1204,10 @@ EXPORT_SYMBOL(pci_enable_link_state); * can't touch the LNKCTL register. Also note that this does not enable states * disabled by pci_disable_link_state(). Return 0 or a negative errno. * + * Note: The PCIe devices of the link must be in D0, if the PCI-PM L1 PM + * substates are going to be enabled. From Section 5.5.4 of PCIe Base Spec + * Revision 6.0. + * * @pdev: PCI device * @state: Mask of ASPM link states to enable *