Because our context refcounting doesn't grab a ref at lookup time, it is unsafe to do so without the lock. NOTE: We don't have an easy way to put the assertion in the lookup function which is where this really belongs. Context switching is good enough because it actually asserts even more correctness by protecting the default_context. Signed-off-by: Ben Widawsky <ben at bwidawsk.net> --- drivers/gpu/drm/i915/i915_gem_context.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index a1e8ecb..411ace0 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -444,6 +444,8 @@ int i915_switch_context(struct intel_ring_buffer *ring, if (dev_priv->hw_contexts_disabled) return 0; + BUG_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex)); + if (ring != &dev_priv->ring[RCS]) return 0; -- 1.8.2.1
