drm/i915: Require HW contexts (when possible)

v2: Fixed the botched locking on init_hw failure in i915_reset (Ville)
Call cleanup_ringbuffer on failed context create in init_hw (Ville)

v3: Add dev argument ti clean_ringbuffer

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e2d9745..efca30d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1447,7 +1447,6 @@
 	struct drm_property *broadcast_rgb_property;
 	struct drm_property *force_audio_property;
 
-	bool hw_contexts_disabled;
 	uint32_t hw_context_size;
 	struct list_head context_list;
 
@@ -2151,7 +2150,7 @@
 }
 
 /* i915_gem_context.c */
-void i915_gem_context_init(struct drm_device *dev);
+int __must_check i915_gem_context_init(struct drm_device *dev);
 void i915_gem_context_fini(struct drm_device *dev);
 void i915_gem_context_close(struct drm_device *dev, struct drm_file *file);
 int i915_switch_context(struct intel_ring_buffer *ring,