drm/i915: Only mark the ctx as initialised after a SET_CONTEXT operation

Fallout from

commit 46470fc
Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date:   Wed May 21 19:01:06 2014 +0300

    drm/i915: Add null state batch to active list

undid the earlier fix of only marking the ctx as initialised after it is
saved by the hardware during a SET_CONTEXT operation:

commit ad1d219
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Sat Dec 28 13:31:49 2013 -0800

    drm/i915: set ctx->initialized only after RCS

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
[Jani: add reference to the earlier fix in the commit messsage.]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/i915_gem_context.c

@@ -598,6 +598,7 @@ static int do_switch(struct intel_engine_cs *ring,
 	struct intel_context *from = ring->last_context;
 	struct i915_hw_ppgtt *ppgtt = ctx_to_ppgtt(to);
 	u32 hw_flags = 0;
+	bool uninitialized = false;
 	int ret, i;
 
 	if (from != NULL && ring == &dev_priv->ring[RCS]) {
@@ -696,19 +697,20 @@ static int do_switch(struct intel_engine_cs *ring,
 		i915_gem_context_unreference(from);
 	}
 
+	uninitialized = !to->is_initialized && from == NULL;
+	to->is_initialized = true;
+
 done:
 	i915_gem_context_reference(to);
 	ring->last_context = to;
 	to->last_ring = ring;
 
-	if (ring->id == RCS && !to->is_initialized && from == NULL) {
+	if (uninitialized) {
 		ret = i915_gem_render_state_init(ring);
 		if (ret)
 			DRM_ERROR("init render state: %d\n", ret);
 	}
 
-	to->is_initialized = true;
-
 	return 0;
 
 unpin_out: