Mesa (master): intel/gen6: Some framebuffers having separate depthstencil should be unsupported

[Chad Versace]

Module: Mesa
Branch: master
Commit: ba5252e590782a77b8a46d9c0ec4691cf8da6298
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ba5252e590782a77b8a46d9c0ec4691cf8da6298

Author: Chad Versace <chad.versace at linux.intel.com>
Date:   Thu Jan 19 13:08:48 2012 -0800

intel/gen6: Some framebuffers having separate depthstencil should be unsupported

When the framebuffer has separate depth and stencil buffers, and HiZ is
not enabled on the depth buffer, mark the framebuffer as unsupported. This
happens when trying to create a framebuffer with Z16/S8 because we haven't
enabled HiZ on Z16 yet.

Fixes gles2conform test stencil8.

Note: This is a candiate for the 8.0 branch.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44948
Reviewed-and-tested-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed--by: Eric Anholt <eric at anholt.net>
Signed-off-by: Chad Versace <chad.versace at linux.intel.com>

---

 src/mesa/drivers/dri/intel/intel_fbo.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c
index c37075c..45a6827 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.c
+++ b/src/mesa/drivers/dri/intel/intel_fbo.c
@@ -804,6 +804,15 @@ intel_validate_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 	    fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 	 if (stencil_mt->format != MESA_FORMAT_S8)
 	    fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
+	 if (intel->gen < 7 && depth_mt->hiz_mt == NULL) {
+	    /* Before Gen7, separate depth and stencil buffers can be used
+	     * only if HiZ is enabled. From the Sandybridge PRM, Volume 2,
+	     * Part 1, Bit 3DSTATE_DEPTH_BUFFER.SeparateStencilBufferEnable:
+	     *     [DevSNB]: This field must be set to the same value (enabled
+	     *     or disabled) as Hierarchical Depth Buffer Enable.
+	     */
+	    fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED;
+	 }
       }
    }