[PATCH v2 43/49] PCI: Get new realloc size for bridge for last try

[Yinghai Lu <yinghai@kernel.org>]

Current realloc path would not shrink bridge resource through
pbus_size_mem() checking with the old size.

That cause problem: when "must+optional" resource allocation fails,
the cached bridge resource size will prevent "must" resource to get
allocated smaller resource.

Clear the old resource size for last try or third and later try.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=81431
Tested-by: TJ <linux@iam.tj>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/setup-bus.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index da0a259..7ffb113 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2327,8 +2327,15 @@ again:
 		struct resource *res = fail_res->res;
 
 		restore_resource(fail_res, res);
-		if (fail_res->dev->subordinate)
+		if (fail_res->dev->subordinate) {
 			res->flags = 0;
+			/* last or third times and later */
+			if (tried_times + 1 == pci_try_num ||
+			    tried_times + 1 > 2) {
+				res->start = 0;
+				res->end = res->start - 1;
+			}
+		}
 	}
 	free_list(&fail_head);
 
@@ -2400,8 +2407,12 @@ again:
 		struct resource *res = fail_res->res;
 
 		restore_resource(fail_res, res);
-		if (fail_res->dev->subordinate)
+		if (fail_res->dev->subordinate) {
 			res->flags = 0;
+			/* last time */
+			res->start = 0;
+			res->end = res->start - 1;
+		}
 	}
 	free_list(&fail_head);
 
-- 
1.8.4.5