Merge: PCI: Fix active state requirement in PME polling

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/3746

JIRA: https://issues.redhat.com/browse/RHEL-25125

Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=for-linus

Testing: Verified by upstream bugzilla reporter to resolve regression (see upstream bugzilla link and link to upstream thread in commit), verified internally to maintain fix for RH BZ2216699, where the original fix introduced the regression.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Approved-by: John W. Linville <linville@redhat.com>
Approved-by: Myron Stowe <mstowe@redhat.com>
Approved-by: Eric Auger <eric.auger@redhat.com>

Merged-by: Scott Weaver <scweaver@redhat.com>

Author: swvrrh

drivers/pci/pci.c

@@ -2425,29 +2425,36 @@ static void pci_pme_list_scan(struct work_struct *work)
 		if (pdev->pme_poll) {
 			struct pci_dev *bridge = pdev->bus->self;
 			struct device *dev = &pdev->dev;
-			int pm_status;
+			struct device *bdev = bridge ? &bridge->dev : NULL;
+			int bref = 0;
 
 			/*
-			 * If bridge is in low power state, the
-			 * configuration space of subordinate devices
-			 * may be not accessible
+			 * If we have a bridge, it should be in an active/D0
+			 * state or the configuration space of subordinate
+			 * devices may not be accessible or stable over the
+			 * course of the call.
 			 */
-			if (bridge && bridge->current_state != PCI_D0)
-				continue;
+			if (bdev) {
+				bref = pm_runtime_get_if_active(bdev, true);
+				if (!bref)
+					continue;
+
+				if (bridge->current_state != PCI_D0)
+					goto put_bridge;
+			}
 
 			/*
-			 * If the device is in a low power state it
-			 * should not be polled either.
+			 * The device itself should be suspended but config
+			 * space must be accessible, therefore it cannot be in
+			 * D3cold.
 			 */
-			pm_status = pm_runtime_get_if_active(dev, true);
-			if (!pm_status)
-				continue;
-
-			if (pdev->current_state != PCI_D3cold)
+			if (pm_runtime_suspended(dev) &&
+			    pdev->current_state != PCI_D3cold)
 				pci_pme_wakeup(pdev, NULL);
 
-			if (pm_status > 0)
-				pm_runtime_put(dev);
+put_bridge:
+			if (bref > 0)
+				pm_runtime_put(bdev);
 		} else {
 			list_del(&pme_dev->list);
 			kfree(pme_dev);