Only along the submission path can we guarantee that the locked request is indeed from a foreign engine, and so the nesting of engine/rq is permissible. On the submission tasklet (process_csb()), we may find ourselves competing with the normal nesting of rq/engine, invalidating our nesting. As we only use the spinlock for debug purposes, skip the debug if we cannot acquire the spinlock for safe validation - catching 99% of the bugs is better than causing a hard lockup. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 37ab9742abe7..82807918382d 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1315,8 +1315,8 @@ assert_pending_valid(const struct intel_engine_execlists *execlists, ce = rq->hw_context; /* Hold tightly onto the lock to prevent concurrent retires! */ - spin_lock_irqsave_nested(&rq->lock, flags, - SINGLE_DEPTH_NESTING); + if (!spin_trylock_irqsave(&rq->lock, flags)) + continue; if (i915_request_completed(rq)) goto unlock; -- 2.24.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
