[Mesa-dev] [PATCH 3/5] i965/gen9: Resolve SRGB color buffers when GL_FRAMEBUFFER_SRGB enabled

[Neil Roberts]

SKL can't cope with the CCS buffer for SRGB buffers. Normally the
hardware won't see the SRGB formats because when GL_FRAMEBUFFER_SRGB
is disabled these get mapped to their linear equivalents. In order to
avoid relying on the CCS buffer when it is enabled this patch now
makes it flush the renderbuffers.
---

I made a test case for this here:

http://patchwork.freedesktop.org/patch/66225/

 src/mesa/drivers/dri/i965/brw_context.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 7e2fdcb..a8c1052 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -197,6 +197,31 @@ intel_update_state(struct gl_context * ctx, GLuint new_state)
       brw_render_cache_set_check_flush(brw, tex_obj->mt->bo);
    }
 
+   /* If FRAMEBUFFER_SRGB is used on Gen9+ then we need to resolve any of the
+    * single-sampled color renderbuffers because the CCS buffer isn't
+    * supported for SRGB formats and the blending wouldn't work.
+    */
+   if (brw->gen >= 9 && ctx->Color.sRGBEnabled) {
+      struct gl_framebuffer *fb = ctx->DrawBuffer;
+      for (int i = 0; i < fb->_NumColorDrawBuffers; i++) {
+         struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[i];
+
+         if (rb == NULL)
+            continue;
+
+         struct intel_renderbuffer *irb = intel_renderbuffer(rb);
+         struct intel_mipmap_tree *mt = irb->mt;
+
+         if (mt == NULL ||
+             mt->num_samples > 1 ||
+             _mesa_get_srgb_format_linear(mt->format) == mt->format)
+               continue;
+
+         intel_miptree_resolve_color(brw, mt);
+         brw_render_cache_set_check_flush(brw, mt->bo);
+      }
+   }
+
    _mesa_lock_context_textures(ctx);
 }
 
-- 
1.9.3