drm/i915/gt: One more flush for Baytrail clear residuals

CI reports that Baytail requires one more invalidate after CACHE_MODE
for it to be happy.

Fixes: ace44e1 ("drm/i915/gt: Clear CACHE_MODE prior to clearing residuals")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210119110802.22228-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/gen7_renderclear.c

@@ -353,19 +353,21 @@ static void gen7_emit_pipeline_flush(struct batch_chunk *batch)
 
 static void gen7_emit_pipeline_invalidate(struct batch_chunk *batch)
 {
-	u32 *cs = batch_alloc_items(batch, 0, 8);
+	u32 *cs = batch_alloc_items(batch, 0, 10);
 
 	/* ivb: Stall before STATE_CACHE_INVALIDATE */
-	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = GFX_OP_PIPE_CONTROL(5);
 	*cs++ = PIPE_CONTROL_STALL_AT_SCOREBOARD |
 		PIPE_CONTROL_CS_STALL;
 	*cs++ = 0;
 	*cs++ = 0;
+	*cs++ = 0;
 
-	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = GFX_OP_PIPE_CONTROL(5);
 	*cs++ = PIPE_CONTROL_STATE_CACHE_INVALIDATE;
 	*cs++ = 0;
 	*cs++ = 0;
+	*cs++ = 0;
 
 	batch_advance(batch, cs);
 }
@@ -397,6 +399,7 @@ static void emit_batch(struct i915_vma * const vma,
 	batch_add(&cmds, 0xffff0000);
 	batch_add(&cmds, i915_mmio_reg_offset(CACHE_MODE_1));
 	batch_add(&cmds, 0xffff0000 | PIXEL_SUBSPAN_COLLECT_OPT_DISABLE);
+	gen7_emit_pipeline_invalidate(&cmds);
 	gen7_emit_pipeline_flush(&cmds);
 
 	/* Switch to the media pipeline and our base address */