radeon: Add DRI2 flush extension support, so we synchronize properly.

When a DRI2 swap buffer is pending we need to make sure we
have the flush extension so radeon doesn't resume rendering to
or reading from the not yet blitted front buffer.

This fixes:

https://bugs.freedesktop.org/show_bug.cgi?id=28341
https://bugs.freedesktop.org/show_bug.cgi?id=28410

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>

1 files changed, 49 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/radeon/radeon_common_context.c b/src/mesa/drivers/dri/radeon/radeon_common_context.c
index 5a7d52c4d2..f76c49eada 100644
--- a/src/mesa/drivers/dri/radeon/radeon_common_context.c
+++ b/src/mesa/drivers/dri/radeon/radeon_common_context.c
@@ -493,6 +493,50 @@ radeon_bits_per_pixel(const struct radeon_renderbuffer *rb)
    return _mesa_get_format_bytes(rb->base.Format) * 8; 
 }
 
+/*
+ * Check if drawable has been invalidated by dri2InvalidateDrawable().
+ * Update renderbuffers if so. This prevents a client from accessing
+ * a backbuffer that has a swap pending but not yet completed.
+ *
+ * See intel_prepare_render for equivalent code in intel driver.
+ *
+ */
+void radeon_prepare_render(radeonContextPtr radeon)
+{
+    __DRIcontext *driContext = radeon->dri.context;
+    __DRIdrawable *drawable;
+    __DRIscreen *screen;
+
+    screen = driContext->driScreenPriv;
+    if (!screen->dri2.loader)
+        return;
+
+    drawable = driContext->driDrawablePriv;
+    if (drawable->dri2.stamp != driContext->dri2.draw_stamp) {
+	if (drawable->lastStamp != drawable->dri2.stamp)
+	    radeon_update_renderbuffers(driContext, drawable, GL_FALSE);
+
+	/* Intel driver does the equivalent of this, no clue if it is needed:
+	 * radeon_draw_buffer(radeon->glCtx, &(drawable->driverPrivate)->base);
+	 */
+	driContext->dri2.draw_stamp = drawable->dri2.stamp;
+    }
+
+    drawable = driContext->driReadablePriv;
+    if (drawable->dri2.stamp != driContext->dri2.read_stamp) {
+	if (drawable->lastStamp != drawable->dri2.stamp)
+	    radeon_update_renderbuffers(driContext, drawable, GL_FALSE);
+	driContext->dri2.read_stamp = drawable->dri2.stamp;
+    }
+
+    /* If we're currently rendering to the front buffer, the rendering
+     * that will happen next will probably dirty the front buffer.  So
+     * mark it as dirty here.
+     */
+    if (radeon->is_front_buffer_rendering)
+	radeon->front_buffer_dirty = GL_TRUE;
+}
+
 void
 radeon_update_renderbuffers(__DRIcontext *context, __DRIdrawable *drawable,
 			    GLboolean front_only)
@@ -514,6 +558,11 @@ radeon_update_renderbuffers(__DRIcontext *context, __DRIdrawable *drawable,
 	screen = context->driScreenPriv;
 	radeon = (radeonContextPtr) context->driverPrivate;
 
+	/* Set this up front, so that in case our buffers get invalidated
+	 * while we're getting new buffers, we don't clobber the stamp and
+	 * thus ignore the invalidate. */
+	drawable->lastStamp = drawable->dri2.stamp;
+
 	if (screen->dri2.loader
 	   && (screen->dri2.loader->base.version > 2)
 	   && (screen->dri2.loader->getBuffersWithFormat != NULL)) {