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| author |   David E. Box <david.e.box@linux.intel.com> | 2020-12-07 14:39:50 -0800 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2020-12-10 14:43:54 -0600 |
| commit | 39850ed51062f89cd46214a16aaafba5ca49fd6c (patch) | |
| tree | b8cb10061b1aecb2eb14001219f1bf8277565354 /drivers/pci/pci.h | |
| parent | Linux 5.10-rc3 (diff) | |
| download | linux-dev-39850ed51062f89cd46214a16aaafba5ca49fd6c.tar.xz linux-dev-39850ed51062f89cd46214a16aaafba5ca49fd6c.zip | |
PCI/PTM: Save/restore Precision Time Measurement Capability for suspend/resume
The PCI subsystem does not currently save and restore the configuration
space for the Precision Time Measurement (PTM) Extended Capability leading
to the possibility of the feature returning disabled on S3 resume. This
has been observed on Intel Coffee Lake desktops. Add save/restore of the
PTM control register. This saves the PTM Enable, Root Select, and Effective
Granularity bits.
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20201207223951.19667-1-david.e.box@linux.intel.com
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pci.h')
| -rw-r--r-- | drivers/pci/pci.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index f86cae9aa1f4..e0f9e7259e47 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -516,6 +516,14 @@ static inline int pci_iov_bus_range(struct pci_bus *bus) #endif /* CONFIG_PCI_IOV */ +#ifdef CONFIG_PCIE_PTM +void pci_save_ptm_state(struct pci_dev *dev); +void pci_restore_ptm_state(struct pci_dev *dev); +#else +static inline void pci_save_ptm_state(struct pci_dev *dev) { } +static inline void pci_restore_ptm_state(struct pci_dev *dev) { } +#endif + unsigned long pci_cardbus_resource_alignment(struct resource *); static inline resource_size_t pci_resource_alignment(struct pci_dev *dev, |