Commit dd878c0c authored by Maarten Lankhorst's avatar Maarten Lankhorst Committed by Joonas Lahtinen
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drm/i915: Dirty hack to fix selftests locking inversion 



Some i915 selftests still use i915_vma_lock() as inner lock, and
intel_context_create_request() intel_timeline->mutex as outer lock.
Fortunately for selftests this is not an issue, they should be fixed
but we can move ahead and cleanify lockdep now.

Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-19-maarten.lankhorst@linux.intel.com


Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
parent f00ecc2e

drivers/gpu/drm/i915/gt/intel_context.c

+12 −0
Original line number Diff line number Diff line
@@ -459,6 +459,18 @@ struct i915_request *intel_context_create_request(struct intel_context *ce) 
	rq = i915_request_create(ce);

	intel_context_unpin(ce);



	if (IS_ERR(rq))

		return rq;



	/*

	 * timeline->mutex should be the inner lock, but is used as outer lock.

	 * Hack around this to shut up lockdep in selftests..

	 */

	lockdep_unpin_lock(&ce->timeline->mutex, rq->cookie);

	mutex_release(&ce->timeline->mutex.dep_map, _RET_IP_);

	mutex_acquire(&ce->timeline->mutex.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);

	rq->cookie = lockdep_pin_lock(&ce->timeline->mutex);



	return rq;

}