diff options
| author | Bjorn Helgaas <bhelgaas@google.com> | 2024-03-06 00:15:25 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-03-12 20:09:11 +0300 |
| commit | 64dbb2d707444f691539fb12aacf81797786c10b (patch) | |
| tree | 1c8db6a59e1c466528413171717814af94fb862c /drivers/pci/pcie | |
| parent | c198fafa0125e97728d16411aa653602900ab0bc (diff) | |
| download | linux-64dbb2d707444f691539fb12aacf81797786c10b.tar.xz | |
PCI/ASPM: Disable L1 before configuring L1 Substates
Per PCIe r6.1, sec 5.5.4, L1 must be disabled while setting ASPM L1 PM
Substates enable bits. Previously this was enforced by clearing
PCI_EXP_LNKCTL_ASPMC before calling pci_restore_aspm_l1ss_state().
Move the L1 (and L0s, although that doesn't seem required) disable into
pci_restore_aspm_l1ss_state() itself so it's closer to the code that
depends on it.
Link: https://lore.kernel.org/r/20240223213733.GA115410@bhelgaas
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 977eca893b2a..1379b8decdf1 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -105,6 +105,7 @@ void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) struct pci_dev *parent = pdev->bus->self; u32 *cap, pl_ctl1, pl_ctl2, pl_l1_2_enable; u32 cl_ctl1, cl_ctl2, cl_l1_2_enable; + u16 clnkctl, plnkctl; /* * In case BIOS enabled L1.2 when resuming, we need to disable it first @@ -129,6 +130,17 @@ void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) pl_ctl2 = *cap++; pl_ctl1 = *cap; + /* Make sure L0s/L1 are disabled before updating L1SS config */ + pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &clnkctl); + pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &plnkctl); + if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, clnkctl) || + FIELD_GET(PCI_EXP_LNKCTL_ASPMC, plnkctl)) { + pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, + clnkctl & ~PCI_EXP_LNKCTL_ASPMC); + pcie_capability_write_word(parent, PCI_EXP_LNKCTL, + plnkctl & ~PCI_EXP_LNKCTL_ASPMC); + } + /* * Disable L1.2 on this downstream endpoint device first, followed * by the upstream @@ -161,6 +173,13 @@ void pci_restore_aspm_l1ss_state(struct pci_dev *pdev) pci_write_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cl_ctl1 | cl_l1_2_enable); } + + /* Restore L0s/L1 if they were enabled */ + if (FIELD_GET(PCI_EXP_LNKCTL_ASPMC, clnkctl) || + FIELD_GET(PCI_EXP_LNKCTL_ASPMC, plnkctl)) { + pcie_capability_write_word(parent, PCI_EXP_LNKCTL, clnkctl); + pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, plnkctl); + } } #ifdef CONFIG_PCIEASPM |