diff options
| author | Vidya Sagar <vidyas@nvidia.com> | 2022-09-13 18:48:22 +0530 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2022-10-04 20:35:40 -0500 |
| commit | 4ff116d0d5fd8a025604b0802d93a2d5f4e465d1 (patch) | |
| tree | a9578e55a122e03ebec0354dd08f88a5d1abdf3c /drivers/pci/pcie | |
| parent | 5e85eba6f50dc288c22083a7e213152bcc4b8208 (diff) | |
| download | linux-4ff116d0d5fd8a025604b0802d93a2d5f4e465d1.tar.bz2 | |
PCI/ASPM: Save L1 PM Substates Capability for suspend/resume
Previously the L1 PM Substates Control Registers (CTL1 and CTL2) weren't
saved and restored during suspend/resume leading to the L1 PM Substates
configuration being lost post-resume.
Save the L1 PM Substates Control Registers so that the configuration is
retained post-resume.
[bhelgaas: drop pci_is_pcie() testing; we can rely on pci_configure_ltr()
having already done that]
Link: https://lore.kernel.org/r/20220913131822.16557-3-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pcie')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index b4bdadc4ac35..016d222b07c7 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -732,6 +732,43 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state) PCI_L1SS_CTL1_L1SS_MASK, val); } +void pci_save_aspm_l1ss_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + u16 l1ss = dev->l1ss; + u32 *cap; + + if (!l1ss) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS); + if (!save_state) + return; + + cap = (u32 *)&save_state->cap.data[0]; + pci_read_config_dword(dev, l1ss + PCI_L1SS_CTL2, cap++); + pci_read_config_dword(dev, l1ss + PCI_L1SS_CTL1, cap++); +} + +void pci_restore_aspm_l1ss_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + u32 *cap, ctl1, ctl2; + u16 l1ss = dev->l1ss; + + if (!l1ss) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS); + if (!save_state) + return; + + cap = (u32 *)&save_state->cap.data[0]; + ctl2 = *cap++; + ctl1 = *cap; + aspm_program_l1ss(dev, ctl1, ctl2); +} + static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) { pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL, |