From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Currently, endpoint devices may not be powered up entirely during runtime resume that follows a D3hot -> D0 transition of the parent bridge. Namely, even if the power state of an endpoint device, as indicated by its PCI_PM_CTRL register, is D0 after powering up its parent bridge, it may be still necessary to bring its ACPI companion into D0 and that should be done before accessing it. However, the current code assumes that reading the PCI_PM_CTRL register is sufficient to establish the endpoint device's power state, which may lead to problems. Address that by forcing a power-up of all PCI devices, including the platform firmware part of it, during runtime resume. Link: https://lore.kernel.org/linux-pm/11967527.O9o76ZdvQC@kreacher Fixes: 5775b843a619 ("PCI: Restore config space on runtime resume despite being unbound") Reported-by: Abhishek Sahu <abhsahu@xxxxxxxxxx> Tested-by: Abhishek Sahu <abhsahu@xxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- drivers/pci/pci-driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-pm/drivers/pci/pci-driver.c =================================================================== --- linux-pm.orig/drivers/pci/pci-driver.c +++ linux-pm/drivers/pci/pci-driver.c @@ -1312,7 +1312,7 @@ static int pci_pm_runtime_resume(struct * to a driver because although we left it in D0, it may have gone to * D3cold when the bridge above it runtime suspended. */ - pci_restore_standard_config(pci_dev); + pci_pm_default_resume_early(pci_dev); if (!pci_dev->driver) return 0;
