commit 3b28251c65e072f826d29a72f40d5f1f1f2bd25a
Author: Emil Velikov <emil.l.velikov@gmail.com>
Date:   Sun Dec 1 13:03:00 2013 +0000

    XXXnouveau: mess around with buffer transfers only when needed
    
    By Ilia Mirkin
    
    Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

diff --git a/src/gallium/drivers/nouveau/nouveau_buffer.c b/src/gallium/drivers/nouveau/nouveau_buffer.c
index 3e04049..3d7f8ec 100644
--- a/src/gallium/drivers/nouveau/nouveau_buffer.c
+++ b/src/gallium/drivers/nouveau/nouveau_buffer.c
@@ -393,7 +393,7 @@ nouveau_buffer_transfer_map(struct pipe_context *pipe,
    if ((usage & PIPE_TRANSFER_UNSYNCHRONIZED) || !buf->mm)
       return map;
 
-   if (nouveau_buffer_busy(buf, usage & PIPE_TRANSFER_READ_WRITE)) {
+   if ((usage & PIPE_TRANSFER_READ) && nouveau_buffer_busy(buf, usage & PIPE_TRANSFER_READ_WRITE)) {
       if (unlikely(usage & PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE)) {
          /* Discarding was not possible, must sync because
           * subsequent transfers might use UNSYNCHRONIZED. */