From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Fri, 8 Apr 2022 20:29:01 +0200
Subject: PCI/PM: Power up all devices during runtime resume
Git-commit: 9a6058312ea941bac3b0ba8c963d7543fc42a288
Patch-mainline: 5.19-rc1
References: git-fixes

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")
Link: https://lore.kernel.org/r/2652115.mvXUDI8C0e@kreacher
Reported-by: Abhishek Sahu <abhsahu@nvidia.com>
Tested-by: Abhishek Sahu <abhsahu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/pci/pci-driver.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1354,7 +1354,7 @@ 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;