Mesa (master): i965: Only update renderbuffers on initial intelMakeCurrent

[Kristian Høgsberg]

Module: Mesa
Branch: master
Commit: 05da4a7a5e7d5bd988cb31f94ed8e1f053d9ee39
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=05da4a7a5e7d5bd988cb31f94ed8e1f053d9ee39

Author: Kristian Høgsberg <krh at bitplanet.net>
Date:   Fri Jan 17 16:55:31 2014 -0800

i965: Only update renderbuffers on initial intelMakeCurrent

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 this step.

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>
Reviewed-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);