Merge tag 'pci-v6.19-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

Pull PCI fixes from Bjorn Helgaas:

 - Fix the pci_do_resource_release_and_resize() failure path, which
   clobbered the intended failure return value (Ilpo Järvinen)

 - Restore resizable BAR size before value because the size determines
   which bits are writable; this fixes i915 and xe regressions (Ilpo
   Järvinen)

* tag 'pci-v6.19-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: Fix Resizable BAR restore order
  PCI: Fix BAR resize rollback path overwriting ret

2 files changed, 20 insertions, 21 deletions

diff --git a/drivers/pci/rebar.c b/drivers/pci/rebar.c
index ecdebdeb2dff..39f8cf3b70d5 100644
--- a/drivers/pci/rebar.c
+++ b/drivers/pci/rebar.c
@@ -295,7 +295,6 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size,
 			int exclude_bars)
 {
 	struct pci_host_bridge *host;
-	int old, ret;
 
 	/* Check if we must preserve the firmware's resource assignment */
 	host = pci_find_host_bridge(dev->bus);
@@ -308,21 +307,6 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size,
 	if (!pci_rebar_size_supported(dev, resno, size))
 		return -EINVAL;
 
-	old = pci_rebar_get_current_size(dev, resno);
-	if (old < 0)
-		return old;
-
-	ret = pci_rebar_set_size(dev, resno, size);
-	if (ret)
-		return ret;
-
-	ret = pci_do_resource_release_and_resize(dev, resno, size, exclude_bars);
-	if (ret)
-		goto error_resize;
-	return 0;
-
-error_resize:
-	pci_rebar_set_size(dev, resno, old);
-	return ret;
+	return pci_do_resource_release_and_resize(dev, resno, size, exclude_bars);
 }
 EXPORT_SYMBOL(pci_resize_resource);
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 6e90f46f52af..a61d38777cdc 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2504,12 +2504,20 @@ int pci_do_resource_release_and_resize(struct pci_dev *pdev, int resno, int size
 	struct resource *b_win, *r;
 	LIST_HEAD(saved);
 	unsigned int i;
-	int ret = 0;
+	int old, ret;
 
 	b_win = pbus_select_window(bus, res);
 	if (!b_win)
 		return -EINVAL;
 
+	old = pci_rebar_get_current_size(pdev, resno);
+	if (old < 0)
+		return old;
+
+	ret = pci_rebar_set_size(pdev, resno, size);
+	if (ret)
+		return ret;
+
 	pci_dev_for_each_resource(pdev, r, i) {
 		if (i >= PCI_BRIDGE_RESOURCES)
 			break;
@@ -2542,7 +2550,15 @@ out:
 	return ret;
 
 restore:
-	/* Revert to the old configuration */
+	/*
+	 * Revert to the old configuration.
+	 *
+	 * BAR Size must be restored first because it affects the read-only
+	 * bits in BAR (the old address might not be restorable otherwise
+	 * due to low address bits).
+	 */
+	pci_rebar_set_size(pdev, resno, old);
+
 	list_for_each_entry(dev_res, &saved, list) {
 		struct resource *res = dev_res->res;
 		struct pci_dev *dev = dev_res->dev;
@@ -2556,8 +2572,7 @@ restore:
 
 		restore_dev_resource(dev_res);
 
-		ret = pci_claim_resource(dev, i);
-		if (ret)
+		if (pci_claim_resource(dev, i))
 			continue;
 
 		if (i < PCI_BRIDGE_RESOURCES) {