From: Dave Airlie <[email protected]>
I assumed all PCI buses had a bridge, but playing with qemu recently, I
discovered vgaarb bug where it wasn't detecting both devices shared a bridge
at the root level.
Don't check for NULL, if two buses have a NULL bridge, assume the share the
root bus.
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
drivers/gpu/vga/vgaarb.c | 44 +++++++++++++++++++++-----------------------
1 files changed, 21 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index c72f1c0..bdde899 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -465,31 +465,29 @@ static void vga_arbiter_check_bridge_sharing(struct
vga_device *vgadev)
while (new_bus) {
new_bridge = new_bus->self;
- if (new_bridge) {
- /* go through list of devices already registered */
- list_for_each_entry(same_bridge_vgadev, &vga_list,
list) {
- bus = same_bridge_vgadev->pdev->bus;
- bridge = bus->self;
-
- /* see if the share a bridge with this device */
- if (new_bridge == bridge) {
- /* if their direct parent bridge is the
same
- as any bridge of this device then it
can't be used
- for that device */
- same_bridge_vgadev->bridge_has_one_vga
= false;
- }
+ /* go through list of devices already registered */
+ list_for_each_entry(same_bridge_vgadev, &vga_list, list) {
+ bus = same_bridge_vgadev->pdev->bus;
+ bridge = bus->self;
+
+ /* see if the share a bridge with this device */
+ if (new_bridge == bridge) {
+ /* if their direct parent bridge is the same
+ as any bridge of this device then it can't
be used
+ for that device */
+ same_bridge_vgadev->bridge_has_one_vga = false;
+ }
- /* now iterate the previous devices bridge
hierarchy */
- /* if the new devices parent bridge is in the
other devices
- hierarchy then we can't use it to control
this device */
- while (bus) {
- bridge = bus->self;
- if (bridge) {
- if (bridge ==
vgadev->pdev->bus->self)
-
vgadev->bridge_has_one_vga = false;
- }
- bus = bus->parent;
+ /* now iterate the previous devices bridge hierarchy */
+ /* if the new devices parent bridge is in the other
devices
+ hierarchy then we can't use it to control this
device */
+ while (bus) {
+ bridge = bus->self;
+ if (bridge) {
+ if (bridge == vgadev->pdev->bus->self)
+ vgadev->bridge_has_one_vga =
false;
}
+ bus = bus->parent;
}
}
new_bus = new_bus->parent;
--
1.7.6
