i965: Disable MCS on Broadwell for now.

v2: Add a perf_debug() message to remind us to come back to this.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>

src/mesa/drivers/dri/i965/intel_mipmap_tree.c

@@ -84,6 +84,14 @@ compute_msaa_layout(struct brw_context *brw, mesa_format format, GLenum target)
    case GL_DEPTH_STENCIL:
       return INTEL_MSAA_LAYOUT_IMS;
    default:
+      /* Disable MCS on Broadwell for now.  We can enable it once things
+       * are working without it.
+       */
+      if (brw->gen >= 8) {
+         perf_debug("Missing CMS support on Broadwell.\n");
+         return INTEL_MSAA_LAYOUT_UMS;
+      }
+
       /* From the Ivy Bridge PRM, Vol4 Part1 p77 ("MCS Enable"):
        *
        *   This field must be set to 0 for all SINT MSRTs when all RT channels