intel: avoid unnecessary front buffer flushing/updating

Before, if we just called glXMakeCurrent() and didn't render anything we'd
still trigger a flushFrontBuffer() call.

Now only set the intel->front_buffer_dirty field at state validation time
just before we draw something.

NOTE: additional calls to intel_check_front_buffer_rendering() might be
needed if I missed some rendering paths.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i915/intel_tris.c b/src/mesa/drivers/dri/i915/intel_tris.c
index c3cbba8404..bc527aae47 100644
--- a/src/mesa/drivers/dri/i915/intel_tris.c
+++ b/src/mesa/drivers/dri/i915/intel_tris.c
@@ -1088,6 +1088,7 @@ intelRenderStart(GLcontext * ctx)
 {
    struct intel_context *intel = intel_context(ctx);
 
+   intel_check_front_buffer_rendering(intel);
    intel->vtbl.render_start(intel_context(ctx));
    intel->vtbl.emit_state(intel);
 }