diff mbox series

[v7,21/26] PCI: hotplug: Don't disable the released bridge windows immediately

Message ID 20200129152937.311162-22-s.miroshnichenko@yadro.com (mailing list archive)
State Superseded, archived
Delegated to: Bjorn Helgaas
Headers show
Series PCI: Allow BAR movement during boot and hotplug | expand

Commit Message

Sergei Miroshnichenko Jan. 29, 2020, 3:29 p.m. UTC 
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" - means marked for recalculation by
setting to zero.

When the 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: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 573d5c67c136..dd94b4ed7358 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1708,7 +1708,8 @@  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;
 	}