On Mon, Jul 02, 2018 at 04:33:29PM -0600, Mathieu Poirier wrote: SNIP > +static int > +perf_event_process_drv_config(struct perf_event *event, char *config_str) > +{ > + int ret = -EINVAL; > + void *drv_data; > + > + /* Make sure ctx.mutex it held */ > + lockdep_assert_held(&event->ctx->mutex); > + > + /* Children take their configuration from their parent */ > + if (WARN_ON_ONCE(event->parent)) > + goto out; > + > + drv_data = event->pmu->drv_config_validate(event, config_str); > + if (!drv_data) > + goto out; what's this check for? doc does not mention that, also the coresight callback does not return NULL jirka -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html