Created attachment 122118 [details]
bad clear

On the vulkan branch fast clear isn't working in normal GL, works fine on master. I couldn't properly bisect because GL isn't working at all in the early history of the vulkan branch on skl.

From what I was able to determine the problem shows up after master commit 8a0c85b "i965/gen9: Enable rep clears on gen9" gets merged into vulkan branch. If I checkout at this commit in master branch it works fine, but at it's merge point to vulkan branch (958fc04) there is already a problem.

This hack seems to help:
diff --git a/src/mesa/drivers/dri/i965/brw_clear.c b/src/mesa/drivers/dri/i965/brw_clear.c
index 841ba5d..dfd08de 100644
--- a/src/mesa/drivers/dri/i965/brw_clear.c
+++ b/src/mesa/drivers/dri/i965/brw_clear.c
@@ -240,7 +240,7 @@ brw_clear(struct gl_context *ctx, GLbitfield mask)
    }
 
    /* Clear color buffers with fast clear or at least rep16 writes. */
-   if (brw->gen >= 6 && (mask & BUFFER_BITS_COLOR)) {
+   if (0) { //brw->gen >= 6 && (mask & BUFFER_BITS_COLOR)) {
       if (brw_meta_fast_clear(brw, fb, mask, partial_clear)) {
          debug_mask("blorp color", mask & BUFFER_BITS_COLOR);
          mask &= ~BUFFER_BITS_COLOR;

Mesa 11.3.0-devel (git-81f30e2)
Intel(R) HD Graphics 530 (Skylake GT2) 
kernel: 4.5.0-rc5+