static int __live_heartbeat_fast(struct intel_engine_cs *engine)
{
+ const unsigned int error_threshold = max(20000u, jiffies_to_usecs(6));
struct intel_context *ce;
struct i915_request *rq;
ktime_t t0, t1;
times[0],
times[ARRAY_SIZE(times) - 1]);
- /* Min work delay is 2 * 2 (worst), +1 for scheduling, +1 for slack */
- if (times[ARRAY_SIZE(times) / 2] > jiffies_to_usecs(6)) {
+ /*
+ * Ideally, the upper bound on min work delay would be something like
+ * 2 * 2 (worst), +1 for scheduling, +1 for slack. In practice, we
+ * are, even with system_wq_highpri, at the mercy of the CPU scheduler
+ * and may be stuck behind some slow work for many millisecond. Such
+ * as our very own display workers.
+ */
+ if (times[ARRAY_SIZE(times) / 2] > error_threshold) {
pr_err("%s: Heartbeat delay was %uus, expected less than %dus\n",
engine->name,
times[ARRAY_SIZE(times) / 2],
- jiffies_to_usecs(6));
+ error_threshold);
err = -EINVAL;
}