From 39850ed51062f89cd46214a16aaafba5ca49fd6c Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Mon, 7 Dec 2020 14:39:50 -0800 Subject: 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 Link: https://lore.kernel.org/r/20201207223951.19667-1-david.e.box@linux.intel.com Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/pci/pci.c') 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); -- cgit v1.2.3