[PATCH 3/4] PCI: Skip state restoration when configuration is inaccessible

[Richard Cheng]

pci_dev_restore() restores state even when the device is inaccessible.
MSI-X restoration can then issue MMIO accesses that trigger DPC.

Check configuration accessibility before restoring state. Keep driver
reset callbacks and reset return values unchanged.

Signed-off-by: Richard Cheng <icheng@xxxxxxxxxx>
---
 drivers/pci/pci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d59a374a350d..9a343f8b5429 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5127,7 +5127,9 @@ static void pci_dev_restore(struct pci_dev *dev)
 	const struct pci_error_handlers *err_handler =
 			dev->driver ? dev->driver->err_handler : NULL;
 
-	pci_restore_state(dev);
+	/* MSI-X restoration may access device MMIO. */
+	if (pci_dev_config_accessible(dev, "restore state"))
+		pci_restore_state(dev);
 
 	/*
 	 * dev->driver->err_handler->reset_done() is protected against
-- 
2.43.0