diff options
| author | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-16 00:11:09 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-16 00:11:09 +0300 |
| commit | 72b3a644bbe994add91249676d77c279b1d92376 (patch) | |
| tree | c63ecbd900f7254d4e0c6adbe7e65a8d6946ede5 /drivers/pci/pci.c | |
| parent | ff163da95b0ce29ce5ce597a1e98b3e528e57750 (diff) | |
| parent | a697f072f5da8d75467be81bec918eb479405615 (diff) | |
| download | linux-72b3a644bbe994add91249676d77c279b1d92376.tar.xz | |
Merge branch 'pci/ptm'
- Save/restore Precision Time Measurement Capability for suspend/resume
(David E. Box)
- Disable PTM during suspend to save power (David E. Box)
* pci/ptm:
PCI: Disable PTM during suspend to save power
PCI/PTM: Save/restore Precision Time Measurement Capability for suspend/resume
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6cdd7e641ca6..b9fecc25d213 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1561,6 +1561,7 @@ int pci_save_state(struct pci_dev *dev) pci_save_aspm_l1ss_state(dev); pci_save_dpc_state(dev); pci_save_aer_state(dev); + pci_save_ptm_state(dev); return pci_save_vc_state(dev); } EXPORT_SYMBOL(pci_save_state); @@ -1673,6 +1674,7 @@ void pci_restore_state(struct pci_dev *dev) pci_restore_vc_state(dev); pci_restore_rebar_state(dev); pci_restore_dpc_state(dev); + pci_restore_ptm_state(dev); pci_aer_clear_status(dev); pci_restore_aer_state(dev); @@ -2602,12 +2604,24 @@ int pci_prepare_to_sleep(struct pci_dev *dev) if (target_state == PCI_POWER_ERROR) return -EIO; + /* + * There are systems (for example, Intel mobile chips since Coffee + * Lake) where the power drawn while suspended can be significantly + * reduced by disabling PTM on PCIe root ports as this allows the + * port to enter a lower-power PM state and the SoC to reach a + * lower-power idle state as a whole. + */ + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) + pci_disable_ptm(dev); + pci_enable_wake(dev, target_state, wakeup); error = pci_set_power_state(dev, target_state); - if (error) + if (error) { pci_enable_wake(dev, target_state, false); + pci_restore_ptm_state(dev); + } return error; } @@ -2645,12 +2659,23 @@ int pci_finish_runtime_suspend(struct pci_dev *dev) dev->runtime_d3cold = target_state == PCI_D3cold; + /* + * There are systems (for example, Intel mobile chips since Coffee + * Lake) where the power drawn while suspended can be significantly + * reduced by disabling PTM on PCIe root ports as this allows the + * port to enter a lower-power PM state and the SoC to reach a + * lower-power idle state as a whole. + */ + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) + pci_disable_ptm(dev); + __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev)); error = pci_set_power_state(dev, target_state); if (error) { pci_enable_wake(dev, target_state, false); + pci_restore_ptm_state(dev); dev->runtime_d3cold = false; } |