drm/i915: reset the GPU on context fini

It's the only way we know how to make the GPU actually forget about the
default context.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 5d9e07e..f0bd30a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -799,7 +799,7 @@
 	return ret;
 }
 
-static int intel_gpu_reset(struct drm_device *dev)
+int intel_gpu_reset(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int ret = -ENODEV;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 03e7f9e..6f29fd1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1184,6 +1184,7 @@
 extern int i915_emit_box(struct drm_device *dev,
 			 struct drm_clip_rect *box,
 			 int DR1, int DR4);
+extern int intel_gpu_reset(struct drm_device *dev);
 extern int i915_reset(struct drm_device *dev);
 extern unsigned long i915_chipset_val(struct drm_i915_private *dev_priv);
 extern unsigned long i915_mch_val(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 5642c40..6dc426a 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -278,6 +278,8 @@
 	i915_gem_object_unpin(dev_priv->ring[RCS].default_context->obj);
 
 	do_destroy(dev_priv->ring[RCS].default_context);
+
+	intel_gpu_reset(dev);
 }
 
 void i915_gem_context_open(struct drm_device *dev, struct drm_file *file)