intel: Fix swrast_render_start() for depthstencil buffers with separate stencil

1. Don't map the depthstencil buffer twice

   Place a guard in intel_renderbuffer_map() to prevent a renderbuffer
   from being mapped twice. This happened if a single buffer was attached to
   the framebuffer's depth and stencil attachment points.  (Interestingly,
   because intel_map_renderbuffer_gtt() is idempotent, the double mapping did
   not cause bugs for depthstencil buffers *without* separate stencil).

2. Stop overriding gl_framebuffer::_DepthBuffer,_StencilBuffer

   Normally, if a depthstencil buffer is attached to the framebuffer's
   depth attachment point, then _mesa_update_framebuffer() installs
   a wrapper depth renderbuffer at gl_framebuffer::_DepthBuffer. Ditto for
   the stencil attachment point and gl_framebuffer::_StencilBuffer

   A depthstencil intel_renderbuffer with separate stencil contains hidden
   depth and stencil renderbuffers, which are the *real* renderbuffers. In
   order to force swrast to work, we were installing, in
   brw_update_draw_buffer(), the hidden renderbuffers at
   gl_framebuffer::_DepthBuffer and _StencilBuffer, thus overriding the
   behavior of _mesa_update_framebuffer().  However, now that
   intel_renderbuffer_map() is implemented with MapRenderbuffer(),
   overriding _mesa_update_framebuffer's introduces bugs.  This patch
   removes the override code.

Fixes several Piglit tests on gen7.

Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Signed-off-by: Chad Versace <[email protected]>

1 files changed, 14 insertions, 8 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_span.c b/src/mesa/drivers/dri/intel/intel_span.c
index afb0f32a833..b103bbd9f7f 100644
--- a/src/mesa/drivers/dri/intel/intel_span.c
+++ b/src/mesa/drivers/dri/intel/intel_span.c
@@ -187,10 +187,13 @@ intel_renderbuffer_map(struct intel_context *intel, struct gl_renderbuffer *rb)
    if (!irb)
       return;
 
-   if (irb->wrapped_depth)
-      intel_renderbuffer_map(intel, irb->wrapped_depth);
-   if (irb->wrapped_stencil)
-      intel_renderbuffer_map(intel, irb->wrapped_stencil);
+   if (rb->Data) {
+      /* Renderbuffer is already mapped. This usually happens when a single
+       * buffer is attached to the framebuffer's depth and stencil attachment
+       * points.
+       */
+      return;
+   }
 
    ctx->Driver.MapRenderbuffer(ctx, rb, 0, 0, rb->Width, rb->Height,
 			       GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
@@ -211,10 +214,13 @@ intel_renderbuffer_unmap(struct intel_context *intel,
    if (!irb)
       return;
 
-   if (irb->wrapped_depth)
-      intel_renderbuffer_unmap(intel, irb->wrapped_depth);
-   if (irb->wrapped_stencil)
-      intel_renderbuffer_unmap(intel, irb->wrapped_stencil);
+   if (!rb->Data) {
+      /* Renderbuffer is already unmapped. This usually happens when a single
+       * buffer is attached to the framebuffer's depth and stencil attachment
+       * points.
+       */
+      return;
+   }
 
    ctx->Driver.UnmapRenderbuffer(ctx, rb);