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| author | David E. Box <david.e.box@linux.intel.com> | 2020-12-07 23:39:50 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-10 21:43:54 +0100 |
| commit | 39850ed51062f89cd46214a16aaafba5ca49fd6c (patch) | |
| tree | b8cb10061b1aecb2eb14001219f1bf8277565354 /drivers/pci/pci.c | |
| parent | Linux 5.10-rc3 (diff) | |
| download | linux-39850ed51062f89cd46214a16aaafba5ca49fd6c.tar.xz linux-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.c')
| -rw-r--r-- | drivers/pci/pci.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e578d34095e9..12ba6351c05b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1566,6 +1566,7 @@ int pci_save_state(struct pci_dev *dev) pci_save_ltr_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); @@ -1677,6 +1678,7 @@ 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); |