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[v10,50/59] PCI: Allow bridge optional only io port resource required size to be 0

Message ID 1456366370-28995-51-git-send-email-yinghai@kernel.org
State Not Applicable
Headers show

Commit Message

Yinghai Lu Feb. 25, 2016, 2:12 a.m. UTC
When there is no child device under the non hotplug bridge,
We can use 0 for required size, and do not use old size as required size.

That will save some io port range for other bridges, as BIOS could do
some partial assign, and we want to use those not used io port range.

When there is child device, size will not be 0.
when the bridge supports hotplug, min_size will not be 0.
So they will still honor the old size as required size.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/setup-bus.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index c13ec01..4c595c5 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1230,8 +1230,9 @@  static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 
 	size = size_aligned_for_isa(size);
 	size += size1;
-	size0 = calculate_size(size, min_size,
-			resource_size(b_res), min_align);
+	if (size || min_size)
+		size0 = calculate_size(size, min_size,
+					resource_size(b_res), min_align);
 	sum_add_size = size_aligned_for_isa(sum_add_size);
 	sum_add_size += sum_add_size1;
 	if (sum_add_size < min_sum_size)
@@ -1247,7 +1248,7 @@  static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 		return;
 	}
 
-	b_res->start = min_align;
+	b_res->start = size0 ? min_align : 0;
 	b_res->end = b_res->start + size0 - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
 	if (size1 > size0 && realloc_head) {