i915tex: Wait for pending scheduled flips before switching vsync pipe.

This avoids hangs when the vblank sequence numbers are not in sync between
pipes, in particular when they run at different refresh rates.

diff --git a/src/mesa/drivers/dri/i915tex/intel_buffers.c b/src/mesa/drivers/dri/i915tex/intel_buffers.c
index 174f3c6..1643957 100644 (file)
--- a/src/mesa/drivers/dri/i915tex/intel_buffers.c
+++ b/src/mesa/drivers/dri/i915tex/intel_buffers.c
@@ -300,8 +300,27 @@ intelWindowMoved(struct intel_context *intel)
       }
 
       if (flags != intel_fb->vblank_flags) {
+        drmVBlank vbl;
+        int i;
+
+        vbl.request.type = DRM_VBLANK_ABSOLUTE;
+
+        if ( intel_fb->vblank_flags & VBLANK_FLAG_SECONDARY ) {
+           vbl.request.type |= DRM_VBLANK_SECONDARY;
+        }
+
+        for (i = 0; i < intel_fb->pf_num_pages; i++) {
+           vbl.request.sequence = intel_fb->color_rb[i]->vbl_pending;
+           drmWaitVBlank(intel->driFd, &vbl);
+        }
+
         intel_fb->vblank_flags = flags;
         driGetCurrentVBlank(dPriv, intel_fb->vblank_flags, &intel_fb->vbl_seq);
+        intel_fb->vbl_waited = intel_fb->vbl_seq;
+
+        for (i = 0; i < intel_fb->pf_num_pages; i++) {
+           intel_fb->color_rb[i]->vbl_pending = intel_fb->vbl_waited;
+        }
       }
    } else {
       intel_fb->vblank_flags &= ~VBLANK_FLAG_SECONDARY;