[PATCH v2 03/28] coresight: etm3x: Always set tracer's device mode on target CPU
Leo Yan
leo.yan at arm.com
Wed Jul 2 03:42:46 PDT 2025
On Wed, Jul 02, 2025 at 11:18:21AM +0100, Yeoreum Yun wrote:
> Hi Leo,
>
> [...]
> > @@ -464,17 +477,29 @@ static int etm_enable_perf(struct coresight_device *csdev,
> > struct perf_event *event,
> > struct coresight_path *path)
> > {
> > + int ret = 0;
> > struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> >
> > - if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
> > - return -EINVAL;
> > + if (!coresight_take_mode(csdev, CS_MODE_PERF))
> > + return -EBUSY;
> > +
> > + if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) {
> > + ret = -EINVAL;
> > + goto out;
> > + }
>
> Small question: why drvdata->cpu != smp_processor_id() check after
> changing mode? Would it better to check before change of it?
You are right. I will update in next version.
Thanks for pointing out this!
Leo
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