Mesa (master): vc4: Don' t allocate new BOs to avoid synchronization when they're shared.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: e8ea42d245cb6adc7f16ee4e96fd89d905d2163a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=e8ea42d245cb6adc7f16ee4e96fd89d905d2163a

Author: Eric Anholt <eric at anholt.net>
Date:   Wed May 17 13:22:39 2017 -0700

vc4: Don't allocate new BOs to avoid synchronization when they're shared.

If X11 did a software fallback to the entire screen, we would throw out
the BO the screen is scanning out from and allocate a new one.

Cc: mesa-stable at lists.freedesktop.org

---

 src/gallium/drivers/vc4/vc4_resource.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/vc4/vc4_resource.c b/src/gallium/drivers/vc4/vc4_resource.c
index c0bfc8ff2e..8a5398d9f7 100644
--- a/src/gallium/drivers/vc4/vc4_resource.c
+++ b/src/gallium/drivers/vc4/vc4_resource.c
@@ -165,7 +165,8 @@ vc4_resource_transfer_map(struct pipe_context *pctx,
             prsc->width0 == box->width &&
             prsc->height0 == box->height &&
             prsc->depth0 == box->depth &&
-            prsc->array_size == 1) {
+            prsc->array_size == 1 &&
+            rsc->bo->private) {
                 usage |= PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE;
         }