From 8f2b4b684ae530cf7623cc1df22f05460b84cc5e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 19 Oct 2020 15:28:41 +0100 Subject: [PATCH] drm/i915/selftests: Flush the old heartbeat more gently In order to test how fast the heartbeat can respond, we measure with the interval set to its minimum. Before we measure though, we want to be sure we start with a fresh pulse, and so wait until any old one is complete. During that wait though, we were continually flushing the work, and so continually re-evaluating to see if the pulse was complete, and each attempt would count as an unresponsive system. If the engine did not complete the request in the couple of busy-spins, it would flag an error. This is unfortunate, so let's not busy-spin waiting for the old heartbeat, but terminate it and start afresh. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20201019142841.32273-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c index e73854d..b88aa35 100644 --- a/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c @@ -215,16 +215,17 @@ static int __live_heartbeat_fast(struct intel_engine_cs *engine) goto err_pm; for (i = 0; i < ARRAY_SIZE(times); i++) { - /* Manufacture a tick */ do { - while (READ_ONCE(engine->heartbeat.systole)) - flush_delayed_work(&engine->heartbeat.work); + /* Manufacture a tick */ + intel_engine_park_heartbeat(engine); + GEM_BUG_ON(engine->heartbeat.systole); + engine->serial++; /* pretend we are not idle! */ + intel_engine_unpark_heartbeat(engine); - engine->serial++; /* quick, pretend we are not idle! */ flush_delayed_work(&engine->heartbeat.work); if (!delayed_work_pending(&engine->heartbeat.work)) { - pr_err("%s: heartbeat did not start\n", - engine->name); + pr_err("%s: heartbeat %d did not start\n", + engine->name, i); err = -EINVAL; goto err_pm; } -- 2.7.4