Mesa (master): i965/gen9: Only allow Y-Tiled MCS buffers

[Ben Widawsky]

Module: Mesa
Branch: master
Commit: b91a110d5ce946abe0ee84625498676ac4bcf7aa
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b91a110d5ce946abe0ee84625498676ac4bcf7aa

Author: Ben Widawsky <benjamin.widawsky at intel.com>
Date:   Fri May 22 18:13:24 2015 -0700

i965/gen9: Only allow Y-Tiled MCS buffers

For GEN9, much of the logic to use X-Tiled buffers has been stripped out. It is
still supported in some places, but it's never desirable. Unfortunately we don't
yet have the ability to have Y-Tiled scanout (see:
http://patchwork.freedesktop.org/patch/46984/),

NOTE: This patch shouldn't actually do anything since SKL doesn't yet use fast
clears (they are disabled because they are causing regressions). THerefore, the
only case we can get to this function on SKL is by way of
intel_update_winsys_renderbuffer_miptree.

v2: Update commit message to be more clear that the NOTE is for SKL only.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
Reviewed-by: Chad Versace <chad.versace at intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>
Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>

---

 src/mesa/drivers/dri/i965/intel_mipmap_tree.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
index fb4e5b8..cbb91dc 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
@@ -193,6 +193,8 @@ intel_is_non_msrt_mcs_buffer_supported(struct brw_context *brw,
       return false;
    }
 
+   if (brw->gen >= 9 && mt->tiling != I915_TILING_Y)
+      return false;
    if (mt->tiling != I915_TILING_X &&
        mt->tiling != I915_TILING_Y)
       return false;