gallium: use MAP_DIRECTLY to mean supression of DISCARD in buffer_subdata

This is needed to fix an issue with OpenGL when a buffer is mapped and
BufferSubData is called. In this case, we can't invalidate the buffer range.

2 files changed, 14 insertions, 7 deletions

diff --git a/src/gallium/auxiliary/util/u_threaded_context.c b/src/gallium/auxiliary/util/u_threaded_context.c
index fc448908564..8f5ed4a5a67 100644
--- a/src/gallium/auxiliary/util/u_threaded_context.c
+++ b/src/gallium/auxiliary/util/u_threaded_context.c
@@ -1630,8 +1630,11 @@ tc_buffer_subdata(struct pipe_context *_pipe,
    if (!size)
       return;
 
-   usage |= PIPE_TRANSFER_WRITE |
-            PIPE_TRANSFER_DISCARD_RANGE;
+   usage |= PIPE_TRANSFER_WRITE;
+
+   /* PIPE_TRANSFER_MAP_DIRECTLY supresses implicit DISCARD_RANGE. */
+   if (!(usage & PIPE_TRANSFER_MAP_DIRECTLY))
+      usage |= PIPE_TRANSFER_DISCARD_RANGE;
 
    usage = tc_improve_map_buffer_flags(tc, tres, usage, offset, size);
 
diff --git a/src/gallium/auxiliary/util/u_transfer.c b/src/gallium/auxiliary/util/u_transfer.c
index 3089bcb1f34..1ad47b00399 100644
--- a/src/gallium/auxiliary/util/u_transfer.c
+++ b/src/gallium/auxiliary/util/u_transfer.c
@@ -18,11 +18,15 @@ void u_default_buffer_subdata(struct pipe_context *pipe,
    /* the write flag is implicit by the nature of buffer_subdata */
    usage |= PIPE_TRANSFER_WRITE;
 
-   /* buffer_subdata implicitly discards the rewritten buffer range */
-   if (offset == 0 && size == resource->width0) {
-      usage |= PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE;
-   } else {
-      usage |= PIPE_TRANSFER_DISCARD_RANGE;
+   /* buffer_subdata implicitly discards the rewritten buffer range.
+    * PIPE_TRANSFER_MAP_DIRECTLY supresses that.
+    */
+   if (!(usage & PIPE_TRANSFER_MAP_DIRECTLY)) {
+      if (offset == 0 && size == resource->width0) {
+         usage |= PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE;
+      } else {
+         usage |= PIPE_TRANSFER_DISCARD_RANGE;
+      }
    }
 
    u_box_1d(offset, size, &box);