i965: Use a new miptree to avoid software fallbacks due to drawing offset.

When attaching a small mipmap level to an FBO, the original gen4
didn't have the bits to support rendering to it.  Instead of falling
back, just blit it to a new little miptree just for it, and let it get
revalidated into the stack later just like any other new teximage.

Bug #30365.

1 files changed, 1 insertions, 28 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fallback.c b/src/mesa/drivers/dri/i965/brw_fallback.c
index 7262cf6958..82356a5bc0 100644
--- a/src/mesa/drivers/dri/i965/brw_fallback.c
+++ b/src/mesa/drivers/dri/i965/brw_fallback.c
@@ -80,33 +80,6 @@ static GLboolean do_check_fallback(struct brw_context *brw)
       return GL_TRUE;
    }
 
-   /* _NEW_BUFFERS */
-   if (!brw->has_surface_tile_offset) {
-      for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
-	 struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[i];
-	 struct intel_renderbuffer *irb = intel_renderbuffer(rb);
-
-	 /* The original gen4 hardware couldn't set up WM surfaces pointing
-	  * at an offset within a tile, which can happen when rendering to
-	  * anything but the base level of a texture or the +X face/0 depth.
-	  * This was fixed with the 4 Series hardware.
-	  *
-	  * For these original chips, you would have to make the depth and
-	  * color destination surfaces include information on the texture
-	  * type, LOD, face, and various limits to use them as a destination.
-	  * I would have done this, but there's also a nasty requirement that
-	  * the depth and the color surfaces all be of the same LOD, which
-	  * may be a worse requirement than this alignment.  (Also, we may
-	  * want to just demote the texture to untiled, instead).
-	  */
-	 if (irb->region && irb->region->tiling != I915_TILING_NONE &&
-	     (irb->region->draw_offset & 4095)) {
-	    DBG("FALLBACK: non-tile-aligned destination for tiled FBO\n");
-	    return GL_TRUE;
-	 }
-      }
-   }
-
    return GL_FALSE;
 }
 
@@ -117,7 +90,7 @@ static void check_fallback(struct brw_context *brw)
 
 const struct brw_tracked_state brw_check_fallback = {
    .dirty = {
-      .mesa = _NEW_BUFFERS | _NEW_RENDERMODE | _NEW_TEXTURE | _NEW_STENCIL,
+      .mesa = _NEW_RENDERMODE | _NEW_TEXTURE | _NEW_STENCIL,
       .brw  = 0,
       .cache = 0
    },