[PATCH v6 07/30] PCI: hotplug: movable BARs: Don't disable the released bridge windows

[Sergey Miroshnichenko]

On a hotplug event with enabled BAR movement, calculating the new bridge
windows takes some time. During this procedure, the structures that
represent these windows are released - marked for recalculation.

When new bridge windows are ready, they are written to the registers of
every bridge via pci_setup_bridges().

Currently, bridge's registers are updated immediately after releasing a
window to disable it. But if a driver doesn't yet support movable BARs, it
doesn't stop MEM transactions during the hotplug, so disabled bridge
windows will break them.

Let the bridge windows remain operating after releasing, as they will be
updated to the new values in the end of a hotplug event.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko at yadro.com>
---
 drivers/pci/setup-bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 075e8185b936..381ce964cb20 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1588,7 +1588,8 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
 		/* Avoiding touch the one without PREF */
 		if (type & IORESOURCE_PREFETCH)
 			type = IORESOURCE_PREFETCH;
-		__pci_setup_bridge(bus, type);
+		if (!pci_can_move_bars)
+			__pci_setup_bridge(bus, type);
 		/* For next child res under same bridge */
 		r->flags = old_flags;
 	}
-- 
2.23.0