We write to execlists->pending[0] in process_csb() to acknowledge the completion of the ESLP update, outside of the main spinlock. When we check the current status of the previous submission in __execlists_submission_tasklet() we should therefore use READ_ONCE() to reflect and document the unsynchronized read.
Signed-off-by: Chris Wilson <[email protected]> Cc: Tvrtko Ursulin <[email protected]> --- drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index cf6c43bd540a..058484958e87 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -2347,7 +2347,7 @@ static void process_csb(struct intel_engine_cs *engine) static void __execlists_submission_tasklet(struct intel_engine_cs *const engine) { lockdep_assert_held(&engine->active.lock); - if (!engine->execlists.pending[0]) { + if (!READ_ONCE(engine->execlists.pending[0])) { rcu_read_lock(); /* protect peeking at execlists->active */ execlists_dequeue(engine); rcu_read_unlock(); -- 2.25.0 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
