Merge branch 'pci/err'

- For drivers using PCI legacy suspend, save config state at suspend so
  that state (not any earlier state from enumeration, probe, or error
  recovery) will be restored when resuming (Lukas Wunner)

- For devices with no driver or a driver that lacks PM, save config state
  at hibernate so that state (not any earlier state from enumeration,
  probe, or error recovery) will be restored when resuming (Lukas Wunner)

- Save device config space on device addition, before driver binding, so
  error recovery works more reliably (Lukas Wunner)

- Drop pci_save_state() from several drivers that no longer need it since
  the PCI core always does it and pci_restore_state() no longer invalidates
  the saved state (Lukas Wunner)

- Document use of pci_save_state() by drivers to capture the state they
  want restored during error recovery (Lukas Wunner)

* pci/err:
  Documentation: PCI: Amend error recovery doc with pci_save_state() rules
  treewide: Drop pci_save_state() after pci_restore_state()
  PCI/ERR: Ensure error recoverability at all times
  PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw
  PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths

5 files changed, 7 insertions, 8 deletions

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index f26aec6ff588..9daf13ed3714 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -357,6 +357,9 @@ void pci_bus_add_device(struct pci_dev *dev)
 	pci_proc_attach_device(dev);
 	pci_bridge_d3_update(dev);
 
+	/* Save config space for error recoverability */
+	pci_save_state(dev);
+
 	/*
 	 * If the PCI device is associated with a pwrctrl device with a
 	 * power supply, create a device link between the PCI device and
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 302d61783f6c..7c2d9d596258 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -629,6 +629,8 @@ static int pci_legacy_suspend(struct device *dev, pm_message_t state)
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct pci_driver *drv = pci_dev->driver;
 
+	pci_dev->state_saved = false;
+
 	if (drv && drv->suspend) {
 		pci_power_t prev = pci_dev->current_state;
 		int error;
@@ -1036,6 +1038,8 @@ static int pci_pm_freeze(struct device *dev)
 
 	if (!pm) {
 		pci_pm_default_suspend(pci_dev);
+		if (!pm_runtime_suspended(dev))
+			pci_dev->state_saved = false;
 		return 0;
 	}
 
@@ -1129,8 +1133,6 @@ static int pci_pm_thaw(struct device *dev)
 		pci_pm_reenable_device(pci_dev);
 	}
 
-	pci_dev->state_saved = false;
-
 	return error;
 }
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index f4ccb948e59d..2856808ca2e1 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1855,9 +1855,6 @@ static void pci_restore_rebar_state(struct pci_dev *pdev)
  */
 void pci_restore_state(struct pci_dev *dev)
 {
-	if (!dev->state_saved)
-		return;
-
 	pci_restore_pcie_state(dev);
 	pci_restore_pasid_state(dev);
 	pci_restore_pri_state(dev);
diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
index d1b68c18444f..38a41ccf79b9 100644
--- a/drivers/pci/pcie/portdrv.c
+++ b/drivers/pci/pcie/portdrv.c
@@ -760,7 +760,6 @@ static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
 	device_for_each_child(&dev->dev, &off, pcie_port_device_iter);
 
 	pci_restore_state(dev);
-	pci_save_state(dev);
 	return PCI_ERS_RESULT_RECOVERED;
 }
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c3f6e2714440..7da9a431e1cc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2753,8 +2753,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 
 	pci_reassigndev_resource_alignment(dev);
 
-	dev->state_saved = false;
-
 	pci_init_capabilities(dev);
 
 	/*