[Mesa-dev] [PATCH] i965: Only update renderbuffers on initial intelMakeCurrent

[Kristian Høgsberg]

We call intel_prepare_render() in intelMakeCurrent() to make sure we have
renderbuffers before calling _mesa_make_current().  The only reason we
do this is so that we can have valid defaults for width and height.
If we already have buffers for the drawable we're making current, we
don't need to do this.

In itself, this is a small optimization, but it also avoids a round trip
that could block on the display server in a unexpected place.

https://bugs.freedesktop.org/show_bug.cgi?id=72540
https://bugs.freedesktop.org/show_bug.cgi?id=72612

Signed-off-by: Kristian Høgsberg <krh at bitplanet.net>
Review-by: Chad Versace <chad.versace at linux.intel.com>
---
 src/mesa/drivers/dri/i965/brw_context.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 51918b9..173f95a 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -906,6 +906,7 @@ intelMakeCurrent(__DRIcontext * driContextPriv,
    if (driContextPriv) {
       struct gl_context *ctx = &brw->ctx;
       struct gl_framebuffer *fb, *readFb;
+      struct intel_renderbuffer *rb = NULL;
 
       if (driDrawPriv == NULL && driReadPriv == NULL) {
          fb = _mesa_get_incomplete_framebuffer();
@@ -913,6 +914,7 @@ intelMakeCurrent(__DRIcontext * driContextPriv,
       } else {
          fb = driDrawPriv->driverPrivate;
          readFb = driReadPriv->driverPrivate;
+         rb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
          driContextPriv->dri2.draw_stamp = driDrawPriv->dri2.stamp - 1;
          driContextPriv->dri2.read_stamp = driReadPriv->dri2.stamp - 1;
       }
@@ -924,7 +926,12 @@ intelMakeCurrent(__DRIcontext * driContextPriv,
       intel_gles3_srgb_workaround(brw, fb);
       intel_gles3_srgb_workaround(brw, readFb);
 
-      intel_prepare_render(brw);
+      if (rb && !rb->mt) {
+         /* If we don't have buffers for the drawable yet, force a call to
+          * getbuffers here so we can have a default drawable size. */
+         intel_prepare_render(brw);
+      }
+
       _mesa_make_current(ctx, fb, readFb);
    } else {
       _mesa_make_current(NULL, NULL, NULL);
-- 
1.8.4.2