drm/i915: add render state initialization

HW guys say that it is not a cool idea to let device
go into rc6 without proper 3d pipeline state.

For each new uninitialized context, generate a
valid null render state to be run on context
creation.

This patch introduces a skeleton with empty states.

v2: - No need to vmap (Chris Wilson)
    - use .c files for state (Daniel Vetter)
    - no need to flush as i915_add_request does it
    - remove parameter for batch alloc size
    - don't wait for the init (Ben Widawsky)

v3: - move to cpu/gpu (Chris Wilson)

Tested-by: Kristen Carlson Accardi <kristen@linux.intel.com> (v1)
Tested-by: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index f77b4c126465..f7ad59e71b36 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -699,6 +699,12 @@ static int do_switch(struct intel_ring_buffer *ring,
 		/* obj is kept alive until the next request by its active ref */
 		i915_gem_object_ggtt_unpin(from->obj);
 		i915_gem_context_unreference(from);
+	} else {
+		if (to->is_initialized == false) {
+			ret = i915_gem_render_state_init(ring);
+			if (ret)
+				DRM_ERROR("init render state: %d\n", ret);
+		}
 	}
 
 	to->is_initialized = true;