Due to i915_perf assuming that it can use the i915_gem_context reference to protect its i915->gem.contexts.list iteration, we need to defer removal of the context from the list until last reference to the context is put. However, there is a risk of triggering kernel warning on contexts list not empty at driver release time if we deleagate that task to a worker for i915_gem_context_release_work(), unless that work is flushed first. Unfortunately, it is not flushed on driver release. Fix it. Instead of additionally calling flush_workqueue(), either directly or via a new dedicated wrapper around it, replace last call to i915_gem_drain_freed_objects() with existing i915_gem_drain_workqueue() that performs both tasks. Fixes: 75eefd82581f ("drm/i915: Release i915_gem_context from a worker") Suggested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxxxxxxxx> Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxx # v5.16+ --- drivers/gpu/drm/i915/i915_gem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index f18cc6270b2be..2bdddb61ebd7a 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1231,7 +1231,8 @@ void i915_gem_driver_release(struct drm_i915_private *dev_priv) intel_uc_cleanup_firmwares(&to_gt(dev_priv)->uc); - i915_gem_drain_freed_objects(dev_priv); + /* Flush any outstanding work, including i915_gem_context.release_work. */ + i915_gem_drain_workqueue(dev_priv); drm_WARN_ON(&dev_priv->drm, !list_empty(&dev_priv->gem.contexts.list)); } -- 2.25.1