intel: Restore manual flush for old kernels

Daniel Vetter pointed out that the automagic flush by the kernel for the
busy-ioctl was only introduced upstream in 2.6.37. So we still need to
manually emit a flush on old kernels.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/intel_uxa.c b/src/intel_uxa.c
index 24ef6fae..df3adcb3 100644
--- a/src/intel_uxa.c
+++ b/src/intel_uxa.c
@@ -937,7 +937,18 @@ static Bool intel_uxa_get_image(PixmapPtr pixmap,
 
 static void intel_flush_rendering(intel_screen_private *intel)
 {
-    drm_intel_bo_busy(intel->front_buffer);
+	if (intel->needs_flush == 0)
+		return;
+
+	if (intel->has_kernel_flush) {
+		intel_batch_submit(intel->scrn);
+		drm_intel_bo_busy(intel->front_buffer);
+	} else {
+		intel_batch_emit_flush(intel->scrn);
+		intel_batch_submit(intel->scrn);
+	}
+
+	intel->needs_flush = 0;
 }
 
 void intel_uxa_block_handler(intel_screen_private *intel)