[PATCH] exa: add EXA_MIXED_PREFER_UTS

[Maarten Maathuis]

- Drivers using wfb don't like unneeded cpu fallbacks, allow them to signal this.

Signed-off-by: Maarten Maathuis <madman2003 at gmail.com>
---
 exa/exa.h       |    6 ++++++
 exa/exa_accel.c |    6 ++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/exa/exa.h b/exa/exa.h
index 8c93d15..46552c7 100644
--- a/exa/exa.h
+++ b/exa/exa.h
@@ -769,6 +769,12 @@ typedef struct _ExaDriver {
  */
 #define EXA_MIXED_PIXMAPS (1 << 6)
 
+/**
+ * EXA_MIXED_PREFER_UTS indicates that cpu access is more costly than DFS,
+ * which might follow UTS.
+ */
+#define EXA_MIXED_PREFER_UTS (1 << 7)
+
 /** @} */
 
 /* in exa.c */
diff --git a/exa/exa_accel.c b/exa/exa_accel.c
index 1d88acb..b438b1a 100644
--- a/exa/exa_accel.c
+++ b/exa/exa_accel.c
@@ -508,9 +508,11 @@ exaHWCopyNtoN (DrawablePtr    pSrcDrawable,
 	 *
 	 * Not taking this path for mixed pixmaps: It could only save one CPU
 	 * copy between cached memory and risks causing a more expensive
-	 * DownloadFromScreen later on.
+	 * DownloadFromScreen later on. Some drivers may prefer a potential
+	 * DFS to a cpu fallback.
 	 */
-	} else if (!(pExaScr->info->flags & EXA_MIXED_PIXMAPS)) {
+	} else if (!(pExaScr->info->flags & EXA_MIXED_PIXMAPS) ||
+			(pExaScr->info->flags & EXA_MIXED_PREFER_UTS)) {
 	    int bpp = pSrcDrawable->bitsPerPixel;
 	    int src_stride = exaGetPixmapPitch(pSrcPixmap);
 	    CARD8 *src = NULL;
-- 
1.6.5.3